Ice maker and refrigerator including the same

ABSTRACT

An ice maker, according to the present invention, comprises: a first tray forming a part of an ice-making cell; a second tray forming another part the ice-making cell; and a heater which is disposed so as to be adjacent to the first or the second tray, wherein the heater turns on during a period when cold air is being supplied to the ice-making cell, and the output of the on heater can vary.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. patentapplication Ser. No. 17/281,805 filed Mar. 31, 2021, which applicationis a U.S. National Stage Application under 35 U.S.C. § 371 of PCTApplication No. PCT/KR2019/012941, filed Oct. 2, 2019, which claimspriority to Korean Patent Application Nos. 10-2018-0117783, filed Oct.2, 2018, 10-2018-0142117, filed Nov. 16, 2018, and 10-2019-0081688,filed Jul. 6, 2019, whose entire disclosures are hereby incorporated byreference.

BACKGROUND 1. Field

The present disclosure relates to an ice maker and a refrigeratorincluding the same.

2. Background

Ice manufactured using an ice maker applied to a general refrigerator isfrozen in a way that it freezes in all directions. Therefore, air istrapped inside the ice, and because the freezing speed is fast, opaqueice is created.

In order to make transparent ice, there is also a method of making icewhile growing ice in one direction by flowing water from top to bottomor by sprinkling water from bottom to top. However, since ice has to bemade at sub-zero temperatures in the refrigerator, water cannot flow orbe sprinkled. Therefore, this method cannot be applied to an ice makerapplied to a refrigerator.

Therefore, it is necessary to devise a new method in order to make icehaving a spherical shape while being transparent in an ice maker used ina refrigerator.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be described in detail with reference to thefollowing drawings in which like reference numerals refer to likeelements wherein:

FIG. 1(a)-(b) is a front view of a refrigerator according to anembodiment.

FIG. 2 is a side cross-sectional view illustrating a refrigerator inwhich an ice maker is installed.

FIG. 3(a)-(b) is a perspective view of an ice maker according to anembodiment.

FIG. 4(a)-(b) is a front view illustrating an ice maker.

FIG. 5 is an exploded perspective view of an ice maker.

FIGS. 6 to 11 are views illustrating a state in which some components ofthe ice maker are combined.

FIG. 12 is a perspective view of a first tray viewed from belowaccording to an embodiment of the present disclosure.

FIG. 13 is a cross-sectional view of a first tray according to anembodiment of the present disclosure.

FIG. 14 is a perspective view of a second tray viewed from aboveaccording to an embodiment of the present disclosure.

FIG. 15 is a cross-sectional view taken along line 15-15 of FIG. 14 .

FIG. 16 is a top perspective view of a second tray supporter.

FIG. 17 is a cross-sectional view taken along line 17-17 of FIG. 16 .

FIG. 18 is a cross-sectional view taken along line 18-18 of FIG. 3(a).

FIG. 19 is a view illustrating a state in which the second tray is movedto the water supply position in FIG. 18 .

FIGS. 20(a)-c) and 21(a)-(b) are views for explaining a process ofsupplying water to the ice maker.

FIG. 22(a)-(c) is a view for explaining a process of ice being separatedfrom an ice maker.

FIG. 23 is a control block diagram according to an embodiment.

FIG. 24 is a view for explaining an example of a heater applied to anembodiment.

FIG. 25(a)-(b) is a view for explaining a second tray.

FIG. 26 is a view for explaining the operation of the second tray andthe heater.

FIG. 27 is a view for explaining a process of generating ice.

FIG. 28 is a view for explaining a second tray temperature and a heatertemperature.

FIG. 29(a)-(d) is a view for explaining an operation in a case in whichfull ice is not detected in an embodiment of the present disclosure.

FIG. 30(a)-d) is a view for explaining an operation in a case in whichfull ice is detected in an embodiment of the present disclosure.

FIG. 31(a)-(c) is a view for explaining an operation in a case in whichfull ice is not detected in another embodiment of the presentdisclosure.

FIG. 32(a)-(c) is a view for explaining an operation in a case in whichfull ice is detected in another embodiment of the present disclosure.

FIG. 33 is a block diagram of a refrigerator according to anotherembodiment of the present disclosure.

FIG. 34 is a flowchart illustrating a process of generating ice in anice maker according to another embodiment of the present disclosure.

FIG. 35 is a cross-sectional view of an ice maker in a water supplystate.

FIG. 36 is a cross-sectional view of an ice maker in an ice makingstate.

FIG. 37 is a cross-sectional view of an ice maker in a state in whichice making is completed.

FIG. 38 is a cross-sectional view of an ice maker in an initial state ofice separation.

FIG. 39 is a cross-sectional view of an ice maker in a state in whichice separation is completed.

FIG. 40(a)-(b) is a diagram for explaining an output of a second heaterfor each height of ice generated in an ice making cell.

FIG. 41 is a graph illustrating a temperature sensed by a temperaturesensor and an output amount of a second heater during a water supply andice making process.

FIG. 42 is a view illustrating step by step a process in which ice isgenerated for each ice height section.

FIG. 43 is a view for explaining a method for controlling a secondheater in a case in which defrosting of an evaporator starts in an icemaking process.

FIG. 44 is a view for explaining a method for controlling a secondheater in a case in which a target temperature of a freezing compartmentis changed during an ice making process.

FIG. 45 is a graph illustrating a change in output of a second heateraccording to an increase or decrease in a target temperature of afreezing compartment.

FIG. 46 is a view for explaining a method for controlling a secondheater in a case in which a door opening is detected during an icemaking process.

DETAILED DESCRIPTION

Hereinafter, some embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. Itshould be noted that when components in the drawings are designated byreference numerals, the same components have the same reference numeralsas far as possible even though the components are illustrated indifferent drawings. Further, in description of embodiments of thepresent disclosure, when it is determined that detailed descriptions ofwell-known configurations or functions disturb understanding of theembodiments of the present disclosure, the detailed descriptions will beomitted.

Also, in the description of the embodiments of the present disclosure,the terms such as first, second, A, B, (a) and (b) may be used. Each ofthe terms is merely used to distinguish the corresponding component fromother components, and does not delimit an essence, an order or asequence of the corresponding component. It should be understood thatwhen one component is “connected”, “coupled” or “joined” to anothercomponent, the former may be directly connected or jointed to the latteror may be “connected”, coupled” or “joined” to the latter with a thirdcomponent interposed therebetween.

The refrigerator according to an embodiment may include a tray assemblydefining a portion of an ice making cell that is a space in which wateris phase-changed into ice, a cooler supplying cold air to the ice makingcell, a water supply part supplying water to the ice making cell, and acontroller. The refrigerator may further include a temperature sensordetecting a temperature of water or ice of the ice making cell. Therefrigerator may further include a heater disposed adjacent to the trayassembly. The refrigerator may further include a driver to move the trayassembly. The refrigerator may further include a storage chamber inwhich food is stored in addition to the ice making cell. Therefrigerator may further include a cooler supplying cold to the storagechamber. The refrigerator may further include a temperature sensorsensing a temperature in the storage chamber. The controller may controlat least one of the water supply part or the cooler. The controller maycontrol at least one of the heater or the driver.

The controller may control the cooler so that cold is supplied to theice making cell after moving the tray assembly to an ice makingposition. The controller may control the second tray assembly so thatthe second tray assembly moves to an ice separation position in aforward direction so as to take out the ice in the ice making cell whenthe ice is completely made in the ice making cell. The controller maycontrol the tray assembly so that the supply of the water supply partafter the second tray assembly moves to the water supply position in thereverse direction when the ice is completely separated. The controllermay control the tray assembly so as to move to the ice making positionafter the water supply is completed.

According to an embodiment, the storage chamber may be defined as aspace that is controlled to a predetermined temperature by the cooler.An outer case may be defined as a wall that divides the storage chamberand an external space of the storage chamber (i.e., an external space ofthe refrigerator). An insulation material may be disposed between theouter case and the storage chamber. An inner case may be disposedbetween the insulation material and the storage chamber.

According to an embodiment, the ice making cell may be disposed in thestorage chamber and may be defined as a space in which water isphase-changed into ice. A circumference of the ice making cell refers toan outer surface of the ice making cell irrespective of the shape of theice making cell. In another aspect, an outer circumferential surface ofthe ice making cell may refer to an inner surface of the wall definingthe ice making cell. A center of the ice making cell refers to a centerof gravity or volume of the ice making cell. The center may pass througha symmetry line of the ice making cell.

According to an embodiment, the tray may be defined as a wallpartitioning the ice making cell from the inside of the storage chamber.The tray may be defined as a wall defining at least a portion of the icemaking cell. The tray may be configured to surround the whole or aportion of the ice making cell. The tray may include a first portionthat defines at least a portion of the ice making cell and a secondportion extending from a predetermined point of the first portion. Thetray may be provided in plurality. The plurality of trays may contacteach other. For example, the tray disposed at the lower portion mayinclude a plurality of trays. The tray disposed at the upper portion mayinclude a plurality of trays. The refrigerator may include at least onetray disposed under the ice making cell. The refrigerator may furtherinclude a tray disposed above the ice making cell. The first portion andthe second portion may have a structure inconsideration of a degree ofheat transfer of the tray, a degree of cold transfer of the tray, adegree of deformation resistance of the tray, a recovery degree of thetray, a degree of supercooling of the tray, a degree of attachmentbetween the tray and ice solidified in the tray, and coupling forcebetween one tray and the other tray of the plurality of trays.

According to an embodiment, the tray case may be disposed between thetray and the storage chamber. That is, the tray case may be disposed sothat at least a portion thereof surrounds the tray. The tray case may beprovided in plurality. The plurality of tray cases may contact eachother. The tray case may contact the tray to support at least a portionof the tray. The tray case may be configured to connect componentsexcept for the tray (e.g., a heater, a sensor, a power transmissionmember, etc.). The tray case may be directly coupled to the component orcoupled to the component via a medium therebetween. For example, if thewall defining the ice making cell is provided as a thin film, and astructure surrounding the thin film is provided, the thin film may bedefined as a tray, and the structure may be defined as a tray case. Foranother example, if a portion of the wall defining the ice making cellis provided as a thin film, and a structure includes a first portiondefining the other portion of the wall defining the ice making cell anda second part surrounding the thin film, the thin film and the firstportion of the structure are defined as trays, and the second portion ofthe structure is defined as a tray case.

According to an embodiment, the tray assembly may be defined to includeat least the tray. According to an embodiment, the tray assembly mayfurther include the tray case.

According to an embodiment, the refrigerator may include at least onetray assembly connected to the driver to move. The driver is configuredto move the tray assembly in at least one axial direction of the X, Y,or Z axis or to rotate about the axis of at least one of the X, Y, or Zaxis. The embodiment may include a refrigerator having the remainingconfiguration except for the driver and the power transmission memberconnecting the driver to the tray assembly in the contents described inthe detailed description. According to an embodiment, the tray assemblymay move in a first direction.

According to an embodiment, the cooler may be defined as a partconfigured to cool the storage chamber including at least one of anevaporator or a thermoelectric element.

According to an embodiment, the refrigerator may include at least onetray assembly in which the heater is disposed. The heater may bedisposed in the vicinity of the tray assembly to heat the ice makingcell defined by the tray assembly in which the heater is disposed. Theheater may include a heater to be turned on in at least partial sectionwhile the cooler supplies cold so that bubbles dissolved in the waterwithin the ice making cell moves from a portion, at which the ice ismade, toward the water that is in a liquid state to make transparentice. The heater may include a heater (hereinafter referred to as an “iceseparation heater”) controlled to be turned on in at least a sectionafter the ice making is completed so that ice is easily separated fromthe tray assembly. The refrigerator may include a plurality oftransparent ice heaters. The refrigerator may include a plurality of iceseparation heaters. The refrigerator may include a transparent iceheater and an ice separation heater. In this case, the controller maycontrol the ice separation heater so that a heating amount of iceseparation heater is greater than that of transparent ice heater.

According to an embodiment, the tray assembly may include a first regionand a second region, which define an outer circumferential surface ofthe ice making cell. The tray assembly may include a first portion thatdefines at least a portion of the ice making cell and a second portionextending from a predetermined point of the first portion.

For example, the first region may be defined in the first portion of thetray assembly. The first and second regions may be defined in the firstportion of the tray assembly. Each of the first and second regions maybe a portion of the one tray assembly. The first and second regions maybe disposed to contact each other. The first region may be a lowerportion of the ice making cell defined by the tray assembly. The secondregion may be an upper portion of an ice making cell defined by the trayassembly. The refrigerator may include an additional tray assembly. Oneof the first and second regions may include a region contacting theadditional tray assembly. When the additional tray assembly is disposedin a lower portion of the first region, the additional tray assembly maycontact the lower portion of the first region. When the additional trayassembly is disposed in an upper portion of the second region, theadditional tray assembly and the upper portion of the second region maycontact each other.

For another example, the tray assembly may be provided in pluralitycontacting each other. The first region may be disposed in a first trayassembly of the plurality of tray assemblies, and the second region maybe disposed in a second tray assembly. The first region may be the firsttray assembly. The second region may be the second tray assembly. Thefirst and second regions may be disposed to contact each other. At leasta portion of the first tray assembly may be disposed under the icemaking cell defined by the first and second tray assemblies. At least aportion of the second tray assembly may be disposed above the ice makingcell defined by the first and second tray assemblies.

The first region may be a region closer to the heater than the secondregion. The first region may be a region in which the heater isdisposed. The second region may be a region closer to a heat absorbingpart (i.e., a coolant pipe or a heat absorbing part of a thermoelectricmodule) of the cooler than the first region. The second region may be aregion closer to the through-hole supplying cold to the ice making cellthan the first region. To allow the cooler to supply the cold throughthe through-hole, an additional through-hole may be defined in anothercomponent. The second region may be a region closer to the additionalthrough-hole than the first region. The heater may be a transparent iceheater. The heat insulation degree of the second region with respect tothe cold may be less than that of the first region.

The heater may be disposed in one of the first and second trayassemblies of the refrigerator. For example, when the heater is notdisposed on the other one, the controller may control the heater to beturned on in at least a section of the cooler to supply the cold air.For another example, when the additional heater is disposed on the otherone, the controller may control the heater so that the heating amount ofheater is greater than that of additional heater in at least a sectionof the cooler to supply the cold air. The heater may be a transparentice heater.

The embodiment may include a refrigerator having a configurationexcluding the transparent ice heater in the contents described in thedetailed description.

The embodiment may include a pusher including a first edge having asurface pressing the ice or at least one surface of the tray assembly sothat the ice is easily separated from the tray assembly. The pusher mayinclude a bar extending from the first edge and a second edge disposedat an end of the bar. The controller may control the pusher so that aposition of the pusher is changed by moving at least one of the pusheror the tray assembly. The pusher may be defined as a penetrating typepusher, a non-penetrating type pusher, a movable pusher, or a fixedpusher according to a view point.

A through-hole through which the pusher moves may be defined in the trayassembly, and the pusher may be configured to directly press the ice inthe tray assembly. The pusher may be defined as a penetrating typepusher.

The tray assembly may be provided with a pressing part to be pressed bythe pusher, the pusher may be configured to apply a pressure to onesurface of the tray assembly. The pusher may be defined as anon-penetrating type pusher.

The controller may control the pusher to move so that the first edge ofthe pusher is disposed between a first point outside the ice making celland a second point inside the ice making cell.

The pusher may be defined as a movable pusher. The pusher may beconnected to a driver, the rotation shaft of the driver, or the trayassembly that is connected to the driver and is movable. The controllermay control the pusher to move at least one of the tray assemblies sothat the first edge of the pusher is disposed between the first pointoutside the ice making cell and the second point inside the ice makingcell. The controller may control at least one of the tray assemblies tomove to the pusher. Alternatively, the controller may control a relativeposition of the pusher and the tray assembly so that the pusher furtherpresses the pressing part after contacting the pressing part at thefirst point outside the ice making cell. The pusher may be coupled to afixed end. The pusher may be defined as a fixed pusher.

According to an embodiment, the ice making cell may be cooled by thecooler cooling the storage chamber. For example, the storage chamber inwhich the ice making cell is disposed may be a freezing compartmentwhich is controlled at a temperature lower than 0 degree, and the icemaking cell may be cooled by the cooler cooling the freezingcompartment.

The freezing compartment may be divided into a plurality of regions, andthe ice making cell may be disposed in one region of the plurality ofregions.

According to an embodiment, the ice making cell may be cooled by acooler other than the cooler cooling the storage chamber. For example,the storage chamber in which the ice making cell is disposed is arefrigerating compartment which is controlled to a temperature higherthan 0 degree, and the ice making cell may be cooled by a cooler otherthan the cooler cooling the refrigerating compartment. That is, therefrigerator may include a refrigerating compartment and a freezingcompartment, the ice making cell may be disposed inside therefrigerating compartment, and the ice maker cell may be cooled by thecooler that cools the freezing compartment.

The ice making cell may be disposed in a door that opens and closes thestorage chamber.

According to an embodiment, the ice making cell is not disposed insidethe storage chamber and may be cooled by the cooler. For example, theentire storage chamber defined inside the outer case may be the icemaking cell. According to an embodiment, a degree of heat transferindicates a degree of heat transfer from a high-temperature object to alow-temperature object and is defined as a value determined by a shapeincluding a thickness of the object, a material of the object, and thelike. In terms of the material of the object, a high degree of the heattransfer of the object may represent that thermal conductivity of theobject is high. The thermal conductivity may be a unique materialproperty of the object. Even when the material of the object is thesame, the degree of heat transfer may vary depending on the shape of theobject.

The degree of heat transfer may vary depending on the shape of theobject. The degree of heat transfer from a point A to a point B may beinfluenced by a length of a path through which heat is transferred fromthe point A to the point B (hereinafter, referred to as a “heat transferpath”). The more the heat transfer path from the point A to the point Bincreases, the more the degree of heat transfer from the point A to thepoint B may decrease. The more the heat transfer path from the point Ato the point B, the more the degree of heat transfer from the point A tothe point B may increase.

The degree of heat transfer from the point A to the point B may beinfluenced by a thickness of the path through which heat is transferredfrom the point A to the point B. The more the thickness in a pathdirection in which heat is transferred from the point A to the point Bdecreases, the more the degree of heat transfer from the point A to thepoint B may decrease. The greater the thickness in the path directionfrom which the heat from point A to point B is transferred, the more thedegree of heat transfer from point A to point B.

According to an embodiment, a degree of cold transfer indicates a degreeof heat transfer from a low-temperature object to a high-temperatureobject and is defined as a value determined by a shape including athickness of the object, a material of the object, and the like. Thedegree of cold transfer is a term defined in consideration of adirection in which cold air flows and may be regarded as the sameconcept as the degree of heat transfer. The same concept as the degreeof heat transfer will be omitted.

According to an embodiment, a degree of supercooling is a degree ofsupercooling of a liquid and may be defined as a value determined by amaterial of the liquid, a material or shape of a container containingthe liquid, an external factor applied to the liquid during asolidification process of the liquid, and the like. An increase infrequency at which the liquid is supercooled may be seen as an increasein degree of the supercooling. The lowering of the temperature at whichthe liquid is maintained in the supercooled state may be seen as anincrease in degree of the supercooling. Here, the supercooling refers toa state in which the liquid exists in the liquid phase withoutsolidification even at a temperature below a freezing point of theliquid. The supercooled liquid has a characteristic in which thesolidification rapidly occurs from a time point at which thesupercooling is terminated. If it is desired to maintain a rate at whichthe liquid is solidified, it is advantageous to be designed so that thesupercooling phenomenon is reduced.

According to an embodiment, a degree of deformation resistancerepresents a degree to which an object resists deformation due toexternal force applied to the object and is a value determined by ashape including a thickness of the object, a material of the object, andthe like. For example, the external force may include a pressure appliedto the tray assembly in the process of solidifying and expanding waterin the ice making cell. In another example, the external force mayinclude a pressure on the ice or a portion of the tray assembly by thepusher for separating the ice from the tray assembly. For anotherexample, when coupled between the tray assemblies, it may include apressure applied by the coupling.

In terms of the material of the object, a high degree of the deformationresistance of the object may represent that rigidity of the object ishigh. The thermal conductivity may be a unique material property of theobject. Even when the material of the object is the same, the degree ofdeformation resistance may vary depending on the shape of the object.The degree of deformation resistance may be affected by a deformationresistance reinforcement part extending in a direction in which theexternal force is applied. The more the rigidity of the deformationresistant resistance reinforcement part increases, the more the degreeof deformation resistance may increase. The more the height of theextending deformation resistance reinforcement part increase, the morethe degree of deformation resistance may increase.

According to an embodiment, a degree of restoration indicates a degreeto which an object deformed by the external force is restored to a shapeof the object before the external force is applied after the externalforce is removed and is defined as a value determined by a shapeincluding a thickness of the object, a material of the object, and thelike. For example, the external force may include a pressure applied tothe tray assembly in the process of solidifying and expanding water inthe ice making cell. In another example, the external force may includea pressure on the ice or a portion of the tray assembly by the pusherfor separating the ice from the tray assembly. For another example, whencoupled between the tray assemblies, it may include a pressure appliedby the coupling force.

In view of the material of the object, a high degree of the restorationof the object may represent that an elastic modulus of the object ishigh. The elastic modulus may be a material property unique to theobject. Even when the material of the object is the same, the degree ofrestoration may vary depending on the shape of the object. The degree ofrestoration may be affected by an elastic resistance reinforcement partextending in a direction in which the external force is applied. Themore the elastic modulus of the elastic resistance reinforcement partincreases, the more the degree of restoration may increase.

According to an embodiment, the coupling force represents a degree ofcoupling between the plurality of tray assemblies and is defined as avalue determined by a shape including a thickness of the tray assembly,a material of the tray assembly, magnitude of the force that couples thetrays to each other, and the like.

According to an embodiment, a degree of attachment indicates a degree towhich the ice and the container are attached to each other in a processof making ice from water contained in the container and is defined as avalue determined by a shape including a thickness of the container, amaterial of the container, a time elapsed after the ice is made in thecontainer, and the like.

The refrigerator according to an embodiment includes a first trayassembly defining a portion of an ice making cell that is a space inwhich water is phase-changed into ice by cold, a second tray assemblydefining the other portion of the ice making cell, a cooler supplyingcold to the ice making cell, a water supply part supplying water to theice making cell, and a controller. The refrigerator may further includea storage chamber in addition to the ice making cell. The storagechamber may include a space for storing food. The ice making cell may bedisposed in the storage chamber. The refrigerator may further include afirst temperature sensor sensing a temperature in the storage chamber.The refrigerator may further include a second temperature sensor sensinga temperature of water or ice of the ice making cell. The second trayassembly may contact the first tray assembly in the ice making processand may be connected to the driver to be spaced apart from the firsttray assembly in the ice making process. The refrigerator may furtherinclude a heater disposed adjacent to at least one of the first trayassembly or the second tray assembly.

The controller may control at least one of the heater or the driver. Thecontroller may control the cooler so that the cold is supplied to theice making cell after the second tray assembly moves to an ice makingposition when the water is completely supplied to the ice making cell.The controller may control the second tray assembly so that the secondtray assembly moves in a reverse direction after moving to an iceseparation position in a forward direction so as to take out the ice inthe ice making cell when the ice is completely made in the ice makingcell. The controller may control the second tray assembly so that thesupply of the water supply part after the second tray assembly moves tothe water supply position in the reverse direction when the ice iscompletely separated.

Transparent ice will be described. Bubbles are dissolved in water, andthe ice solidified with the bubbles may have low transparency due to thebubbles. Therefore, in the process of water solidification, when thebubble is guided to move from a freezing portion in the ice making cellto another portion that is not yet frozen, the transparency of the icemay increase.

A through-hole defined in the tray assembly may affect the making of thetransparent ice. The through-hole defined in one side of the trayassembly may affect the making of the transparent ice. In the process ofmaking ice, if the bubbles move to the outside of the ice making cellfrom the frozen portion of the ice making cell, the transparency of theice may increase. The through-hole may be defined in one side of thetray assembly to guide the bubbles so as to move out of the ice makingcell. Since the bubbles have lower density than the liquid, thethrough-hole (hereinafter, referred to as an “air exhaust hole”) forguiding the bubbles to escape to the outside of the ice making cell maybe defined in the upper portion of the tray assembly.

The position of the cooler and the heater may affect the making of thetransparent ice. The position of the cooler and the heater may affect anice making direction, which is a direction in which ice is made insidethe ice making cell.

In the ice making process, when bubbles move or are collected from aregion in which water is first solidified in the ice making cell toanother predetermined region in a liquid state, the transparency of themade ice may increase. The direction in which the bubbles move or arecollected may be similar to the ice making direction. The predeterminedregion may be a region in which water is to be solidified lately in theice making cell.

The predetermined region may be a region in which the cold supplied bythe cooler reaches the ice making cell late. For example, in the icemaking process, the through-hole through which the cooler supplies thecold to the ice making cell may be defined closer to the upper portionthan the lower part of the ice making cell so as to move or collect thebubbles to the lower portion of the ice making cell. For anotherexample, a heat absorbing part of the cooler (that is, a refrigerantpipe of the evaporator or a heat absorbing part of the thermoelectricelement) may be disposed closer to the upper portion than the lowerportion of the ice making cell. According to an embodiment, the upperand lower portions of the ice making cell may be defined as an upperregion and a lower region based on a height of the ice making cell.

The predetermined region may be a region in which the heater isdisposed. For example, in the ice making process, the heater may bedisposed closer to the lower portion than the upper portion of the icemaking cell so as to move or collect the bubbles in the water to thelower portion of the ice making cell.

The predetermined region may be a region closer to an outercircumferential surface of the ice making cell than to a center of theice making cell. However, the vicinity of the center is not excluded. Ifthe predetermined region is near the center of the ice making cell, anopaque portion due to the bubbles moved or collected near the center maybe easily visible to the user, and the opaque portion may remain untilmost of the ice until the ice is melted. Also, it may be difficult toarrange the heater inside the ice making cell containing water. Incontrast, when the predetermined region is defined in or near the outercircumferential surface of the ice making cell, water may be solidifiedfrom one side of the outer circumferential surface of the ice makingcell toward the other side of the outer circumferential surface of theice making cell, thereby solving the above limitation. The transparentice heater may be disposed on or near the outer circumferential surfaceof the ice making cell. The heater may be disposed at or near the trayassembly.

The predetermined region may be a position closer to the lower portionof the ice making cell than the upper portion of the ice making cell.However, the upper portion is also not excluded. In the ice makingprocess, since liquid water having greater density than ice drops, itmay be advantageous that the predetermined region is defined in thelower portion of the ice making cell.

At least one of the degree of deformation resistance, the degree ofrestoration, and the coupling force between the plurality of trayassemblies may affect the making of the transparent ice. At least one ofthe degree of deformation resistance, the degree of restoration, and thecoupling force between the plurality of tray assemblies may affect theice making direction that is a direction in which ice is made in the icemaking cell. As described above, the tray assembly may include a firstregion and a second region, which define an outer circumferentialsurface of the ice making cell. For example, each of the first andsecond regions may be a portion of one tray assembly. For anotherexample, the first region may be a first tray assembly. The secondregion may be a second tray assembly.

To make the transparent ice, it may be advantageous for the refrigeratorto be configured so that the direction in which ice is made in the icemaking cell is constant. This is because the more the ice makingdirection is constant, the more the bubbles in the water are moved orcollected in a predetermined region within the ice making cell. It maybe advantageous for the deformation of the portion to be greater thanthe deformation of the other portion so as to induce the ice to be madein the direction of the other portion in a portion of the tray assembly.The ice tends to be grown as the ice is expanded toward a potion atwhich the degree of deformation resistance is low. To start the icemaking again after removing the made ice, the deformed portion has to berestored again to make ice having the same shape repeatedly. Therefore,it may be advantageous that the portion having the low degree of thedeformation resistance has a high degree of the restoration than theportion having a high degree of the deformation resistance.

The degree of deformation resistance of the tray with respect to theexternal force may be less than that of the tray case with respect tothe external force, or the rigidity of the tray may be less than that ofthe tray case. The tray assembly allows the tray to be deformed by theexternal force, while the tray case surrounding the tray is configuredto reduce the deformation. For example, the tray assembly may beconfigured so that at least a portion of the tray is surrounded by thetray case. In this case, when a pressure is applied to the tray assemblywhile the water inside the ice making cell is solidified and expanded,at least a portion of the tray may be allowed to be deformed, and theother part of the tray may be supported by the tray case to restrict thedeformation. In addition, when the external force is removed, the degreeof restoration of the tray may be greater than that of the tray case, orthe elastic modulus of the tray may be greater than that of the traycase. Such a configuration may be configured so that the deformed trayis easily restored.

The degree of deformation resistance of the tray with respect to theexternal force may be greater than that of the gasket of therefrigerator with respect to the external force, or the rigidity of thetray may be greater than that of the gasket. When the degree ofdeformation resistance of the tray is low, there may be a limitationthat the tray is excessively deformed as the water in the ice makingcell defined by the tray is solidified and expanded. Such a deformationof the tray may make it difficult to make the desired type of ice. Inaddition, the degree of restoration of the tray when the external forceis removed may be configured to be less than that of the refrigeratorgasket with respect to the external force, or the elastic modulus of thetray is less than that of the gasket.

The deformation resistance of the tray case with respect to the externalforce may be less than that of the refrigerator case with respect to theexternal force, or the rigidity of the tray case may be less than thatof the refrigerator case. In general, the case of the refrigerator maybe made of a metal material including steel. In addition, when theexternal force is removed, the degree of restoration of the tray casemay be greater than that of the refrigerator case with respect to theexternal force, or the elastic modulus of the tray case is greater thanthat of the refrigerator case.

The relationship between the transparent ice and the degree ofdeformation resistance is as follows.

The second region may have different degree of deformation resistance ina direction along the outer circumferential surface of the ice makingcell. The degree of deformation resistance of the portion of the secondregion may be greater than that of the another of the second region.Such a configuration may be assisted to induce ice to be made in adirection from the ice making cell defined by the second region to theice making cell defined by the first region.

The first and second regions defined to contact each other may havedifferent degree of deformation resistances in the direction along theouter circumferential surface of the ice making cell. The degree ofdeformation resistance of one portion of the second region may begreater than that of one portion of the first region. Such aconfiguration may be assisted to induce ice to be made in a directionfrom the ice making cell defined by the second region to the ice makingcell defined by the first region.

In this case, as the water is solidified, a volume is expanded to applya pressure to the tray assembly, which induces ice to be made in theother direction of the second region or in one direction of the firstregion. The degree of deformation resistance may be a degree thatresists to deformation due to the external force. The external force maya pressure applied to the tray assembly in the process of solidifyingand expanding water in the ice making cell. The external force may beforce in a vertical direction (Z-axis direction) of the pressure. Theexternal force may be force acting in a direction from the ice makingcell defined by the second region to the ice making cell defined by thefirst region.

For example, in the thickness of the tray assembly in the direction ofthe outer circumferential surface of the ice making cell from the centerof the ice making cell, one portion of the second region may be thickerthan the other of the second region or thicker than one portion of thefirst region. One portion of the second region may be a portion at whichthe tray case is not surrounded. The other portion of the second regionmay be a portion surrounded by the tray case. One portion of the firstregion may be a portion at which the tray case is not surrounded. Oneportion of the second region may be a portion defining the uppermostportion of the ice making cell in the second region. The second regionmay include a tray and a tray case locally surrounding the tray. Asdescribed above, when at least a portion of the second region is thickerthan the other part, the degree of deformation resistance of the secondregion may be improved with respect to an external force. A minimumvalue of the thickness of one portion of the second region may begreater than that of the thickness of the other portion of the secondregion or greater than that of one portion of the first region. Amaximum value of the thickness of one portion of the second region maybe greater than that of the thickness of the other portion of the secondregion or greater than that of one portion of the first region. When thethrough-hole is defined in the region, the minimum value represents theminimum value in the remaining regions except for the portion in whichthe through-hole is defined. An average value of the thickness of oneportion of the second region may be greater than that of the thicknessof the other portion of the second region or greater than that of oneportion of the first region. The uniformity of the thickness of oneportion of the second region may be less than that of the thickness ofthe other portion of the second region or less than that of one of thethickness of the first region.

For another example, one portion of the second region may include afirst surface defining a portion of the ice making cell and adeformation resistance reinforcement part extending from the firstsurface in a vertical direction away from the ice making cell defined bythe other of the second region. One portion of the second region mayinclude a first surface defining a portion of the ice making cell and adeformation resistance reinforcement part extending from the firstsurface in a vertical direction away from the ice making cell defined bythe first region. As described above, when at least a portion of thesecond region includes the deformation resistance reinforcement part,the degree of deformation resistance of the second region may beimproved with respect to the external force.

For another example, one portion of the second region may furtherinclude a support surface connected to a fixed end of the refrigerator(e.g., the bracket, the storage chamber wall, etc.) disposed in adirection away from the ice making cell defined by the other of thesecond region from the first surface. One portion of the second regionmay further include a support surface connected to a fixed end of therefrigerator (e.g., the bracket, the storage chamber wall, etc.)disposed in a direction away from the ice making cell defined by thefirst region from the first surface. As described above, when at least aportion of the second region includes a support surface connected to thefixed end, the degree of deformation resistance of the second region maybe improved with respect to the external force.

For another example, the tray assembly may include a first portiondefining at least a portion of the ice making cell and a second portionextending from a predetermined point of the first portion. At least aportion of the second portion may extend in a direction away from theice making cell defined by the first region. At least a portion of thesecond portion may include an additional deformation resistantresistance reinforcement part. At least a portion of the second portionmay further include a support surface connected to the fixed end. Asdescribed above, when at least a portion of the second region furtherincludes the second portion, it may be advantageous to improve thedegree of deformation resistance of the second region with respect tothe external force. This is because the additional deformationresistance reinforcement part is disposed at in the second portion, orthe second portion is additionally supported by the fixed end.

For another example, one portion of the second region may include afirst through-hole. As described above, when the first through-hole isdefined, the ice solidified in the ice making cell of the second regionis expanded to the outside of the ice making cell through the firstthrough-hole, and thus, the pressure applied to the second region may bereduced. In particular, when water is excessively supplied to the icemaking cell, the first through-hole may be contributed to reduce thedeformation of the second region in the process of solidifying thewater.

One portion of the second region may include a second through-holeproviding a path through which the bubbles contained in the water in theice making cell of the second region move or escape. When the secondthrough-hole is defined as described above, the transparency of thesolidified ice may be improved.

In one portion of the second region, a third through-hole may be definedto press the penetrating pusher. This is because it may be difficult forthe non-penetrating type pusher to press the surface of the trayassembly so as to remove the ice when the degree of deformationresistance of the second region increases. The first, second, and thirdthrough-holes may overlap each other. The first, second, and thirdthrough-holes may be defined in one through-hole.

One portion of the second region may include a mounting part on whichthe ice separation heater is disposed. The induction of the ice in theice making cell defined by the second region in the direction of the icemaking cell defined by the first region may represent that the ice isfirst made in the second region. In this case, a time for which the iceis attached to the second region may be long, and the ice separationheater may be required to separate the ice from the second region. Thethickness of the tray assembly in the direction of the outercircumferential surface of the ice making cell from the center of theice making cell may be less than that of the other portion of the secondregion in which the ice separation heater is mounted. This is becausethe heat supplied by the ice separation heater increases in amounttransferred to the ice making cell. The fixed end may be a portion ofthe wall defining the storage chamber or a bracket.

The relation between the coupling force of the transparent ice and thetray assembly is as follows.

To induce the ice to be made in the ice making cell defined by thesecond region in the direction of the ice making cell defined by thefirst region, it may be advantageous to increase in coupling forcebetween the first and second regions arranged to contact each other. Inthe process of solidifying the water, when the pressure applied to thetray assembly while expanded is greater than the coupling force betweenthe first and second regions, the ice may be made in a direction inwhich the first and second regions are separated from each other. In theprocess of solidifying the water, when the pressure applied to the trayassembly while expanded is low, the coupling force between the first andsecond regions is low, it also has the advantage of inducing the ice tobe made so that the ice is made in a direction of the region having thesmallest degree of deformation resistance in the first and secondregions.

There may be various examples of a method of increasing the couplingforce between the first and second regions. For example, after the watersupply is completed, the controller may change a movement position ofthe driver in the first direction to control one of the first and secondregions so as to move in the first direction, and then, the movementposition of the driver may be controlled to be additionally changed intothe first direction so that the coupling force between the first andsecond regions increases. For another example, since the coupling forcebetween the first and second regions increase, the degree of deformationresistances or the degree of restorations of the first and secondregions may be different from each other with respect to the forceapplied from the driver so that the driver reduces the change of theshape of the ice making cell by the expanding the ice after the icemaking process is started (or after the heater is turned on). Foranother example, the first region may include a first surface facing thesecond region. The second region may include a second surface facing thefirst region. The first and second surfaces may be disposed to contacteach other. The first and second surfaces may be disposed to face eachother. The first and second surfaces may be disposed to be separatedfrom and coupled to each other. In this case, surface areas of the firstsurface and the second surface may be different from each other. In thisconfiguration, the coupling force of the first and second regions mayincrease while reducing breakage of the portion at which the first andsecond regions contact each other. In addition, there is an advantage ofreducing leakage of water supplied between the first and second regions.

The relationship between transparent ice and the degree of restorationis as follows.

The tray assembly may include a first portion that defines at least aportion of the ice making cell and a second portion extending from apredetermined point of the first portion. The second portion isconfigured to be deformed by the expansion of the ice made and thenrestored after the ice is removed. The second portion may include ahorizontal extension part provided so that the degree of restorationwith respect to the horizontal external force of the expanded iceincreases. The second portion may include a vertical extension partprovided so that the degree of restoration with respect to the verticalexternal force of the expanded ice increases. Such a configuration maybe assisted to induce ice to be made in a direction from the ice makingcell defined by the second region to the ice making cell defined by thefirst region.

The second region may have different degree of restoration in adirection along the outer circumferential surface of the ice makingcell. The first region may have different degree of deformationresistance in a direction along the outer circumferential surface of theice making cell. The degree of restoration of one portion of the firstregion may be greater than that of the other portion of the firstregion. Also, the degree of deformation resistance of one portion may beless than that of the other portion. Such a configuration may beassisted to induce ice to be made in a direction from the ice makingcell defined by the second region to the ice making cell defined by thefirst region.

The first and second regions defined to contact each other may havedifferent degree of restoration in the direction along the outercircumferential surface of the ice making cell. Also, the first andsecond regions may have different degree of deformation resistances inthe direction along the outer circumferential surface of the ice makingcell. The degree of restoration of one of the first region may begreater than that of one of the second region. Also, the degree ofdeformation resistance of one of the first regions may be greater thanthat of one of the second region. Such a configuration may be assistedto induce ice to be made in a direction from the ice making cell definedby the second region to the ice making cell defined by the first region.

In this case, as the water is solidified, a volume is expanded to applya pressure to the tray assembly, which induces ice to be made in onedirection of the first region in which the degree of deformationresistance decreases, or the degree of restoration increases. Here, thedegree of restoration may be a degree of restoration after the externalforce is removed. The external force may a pressure applied to the trayassembly in the process of solidifying and expanding water in the icemaking cell. The external force may be force in a vertical direction(Z-axis direction) of the pressure. The external force may be forceacting in a direction from the ice making cell defined by the secondregion to the ice making cell defined by the first region.

For example, in the thickness of the tray assembly in the direction ofthe outer circumferential surface of the ice making cell from the centerof the ice making cell, one portion of the first region may be thinnerthan the other of the first region or thinner than one portion of thesecond region. One portion of the first region may be a portion at whichthe tray case is not surrounded. The other portion of the first regionmay be a portion that is surrounded by the tray case. One portion of thesecond region may be a portion that is surrounded by the tray case. Oneportion of the first region may be a portion of the first region thatdefines the lowermost end of the ice making cell. The first region mayinclude a tray and a tray case locally surrounding the tray.

A minimum value of the thickness of one portion of the first region maybe less than that of the thickness of the other portion of the secondregion or less than that of one of the second region. A maximum value ofthe thickness of one portion of the first region may be less than thatof the thickness of the other portion of the first region or less thanthat of the thickness of one portion of the second region. When thethrough-hole is defined in the region, the minimum value represents theminimum value in the remaining regions except for the portion in whichthe through-hole is defined. An average value of the thickness of oneportion of the first region may be less than that of the thickness ofthe other portion of the first region or may be less than that of one ofthe thickness of the second region. The uniformity of the thickness ofone portion of the first region may be greater than that of thethickness of the other portion of the first region or greater than thatof one of the thickness of the second region.

For another example, a shape of one portion of the first region may bedifferent from that of the other portion of the first region ordifferent from that of one portion of the second region. A curvature ofone portion of the first region may be different from that of the otherportion of the first region or different from that of one portion of thesecond region. A curvature of one portion of the first region may beless than that of the other portion of the first region or less thanthat of one portion of the second region. One portion of the firstregion may include a flat surface. The other portion of the first regionmay include a curved surface. One portion of the second region mayinclude a curved surface. One portion of the first region may include ashape that is recessed in a direction opposite to the direction in whichthe ice is expanded. One portion of the first region may include a shaperecessed in a direction opposite to a direction in which the ice ismade. In the ice making process, one portion of the first region may bemodified in a direction in which the ice is expanded or a direction inwhich the ice is made. In the ice making process, in an amount ofdeformation from the center of the ice making cell toward the outercircumferential surface of the ice making cell, one portion of the firstregion is greater than the other portion of the first region. In the icemaking process, in the amount of deformation from the center of the icemaking cell toward the outer circumferential surface of the ice makingcell, one portion of the first region is greater than one portion of thesecond region.

For another example, to induce ice to be made in a direction from theice making cell defined by the second region to the ice making celldefined by the first region, one portion of the first region may includea first surface defining a portion of the ice making cell and a secondsurface extending from the first surface and supported by one surface ofthe other portion of the first region. The first region may beconfigured not to be directly supported by the other component exceptfor the second surface. The other component may be a fixed end of therefrigerator.

One portion of the first region may have a pressing surface pressed bythe non-penetrating type pusher. This is because when the degree ofdeformation resistance of the first region is low, or the degree ofrestoration is high, the difficulty in removing the ice by pressing thesurface of the tray assembly may be reduced.

An ice making rate, at which ice is made inside the ice making cell, mayaffect the making of the transparent ice. The ice making rate may affectthe transparency of the made ice. Factors affecting the ice making ratemay be an amount of cold and/or heat, which are/is supplied to the icemaking cell. The amount of cold and/or heat may affect the making of thetransparent ice. The amount of cold and/or heat may affect thetransparency of the ice.

In the process of making the transparent ice, the transparency of theice may be lowered as the ice making rate is greater than a rate atwhich the bubbles in the ice making cell are moved or collected. On theother hand, if the ice making rate is less than the rate at which thebubbles are moved or collected, the transparency of the ice mayincrease. However, the more the ice making rate decreases, the more atime taken to make the transparent ice may increase. Also, thetransparency of the ice may be uniform as the ice making rate ismaintained in a uniform range.

To maintain the ice making rate uniformly within a predetermined range,an amount of cold and heat supplied to the ice making cell may beuniform. However, in actual use conditions of the refrigerator, a casein which the amount of cold is variable may occur, and thus, it isnecessary to allow a supply amount of heat to vary. For example, when atemperature of the storage chamber reaches a satisfaction region from adissatisfaction region, when a defrosting operation is performed withrespect to the cooler of the storage chamber, the door of the storagechamber may variously vary in state such as an opened state. Also, if anamount of water per unit height of the ice making cell is different,when the same cold and heat per unit height is supplied, thetransparency per unit height may vary.

To solve this limitation, the controller may control the heater so thatwhen a heat transfer amount between the cold within the storage chamberand the water of the ice making cell increases, the heating amount oftransparent ice heater increases, and when the heat transfer amountbetween the cold within the storage chamber and the water of the icemaking cell decreases, the heating amount of transparent ice heaterdecreases so as to maintain an ice making rate of the water within theice making cell within a predetermined range that is less than an icemaking rate when the ice making is performed in a state in which theheater is turned off.

The controller may control one or more of a cold supply amount of coolerand a heat supply amount of heater to vary according to a mass per unitheight of water in the ice making cell. In this case, the transparentice may be provided to correspond to a change in shape of the ice makingcell.

The refrigerator may further include a sensor measuring information onthe mass of water per unit height of the ice making cell, and thecontroller may control one of the cold supply amount of cooler and theheat supply amount of heater based on the information inputted from thesensor.

The refrigerator may include a storage part in which predetermineddriving information of the cooler is recorded based on information onmass per unit height of the ice making cell, and the controller maycontrol the cold supply amount of cooler to be changed based on theinformation.

The refrigerator may include a storage part in which predetermineddriving information of the heater is recorded based on information onmass per unit height of the ice making cell, and the controller maycontrol the heat supply amount of heater to be changed based on theinformation. For example, the controller may control at least one of thecold supply amount of cooler or the heat supply amount of heater to varyaccording to a predetermined time based on the information on the massper unit height of the ice making cell. The time may be a time when thecooler is driven or a time when the heater is driven to make ice. Foranother example, the controller may control at least one of the coldsupply amount of cooler or the heat supply amount of heater to varyaccording to a predetermined temperature based on the information on themass per unit height of the ice making cell. The temperature may be atemperature of the ice making cell or a temperature of the tray assemblydefining the ice making cell.

When the sensor measuring the mass of water per unit height of the icemaking cell is malfunctioned, or when the water supplied to the icemaking cell is insufficient or excessive, the shape of the ice makingwater is changed, and thus the transparency of the made ice maydecrease. To solve this limitation, a water supply method in which anamount of water supplied to the ice making cell is precisely controlledis required. Also, the tray assembly may include a structure in whichleakage of the tray assembly is reduced to reduce the leakage of waterin the ice making cell at the water supply position or the ice makingposition. Also, it is necessary to increase the coupling force betweenthe first and second tray assemblies defining the ice making cell so asto reduce the change in shape of the ice making cell due to theexpansion force of the ice during the ice making. Also, it is necessaryto decrease in leakage in the precision water supply method and the trayassembly and increase in coupling force between the first and secondtray assemblies so as to make ice having a shape that is close to thetray shape.

The degree of supercooling of the water inside the ice making cell mayaffect the making of the transparent ice. The degree of supercooling ofthe water may affect the transparency of the made ice.

To make the transparent ice, it may be desirable to design the degree ofsupercooling or lower the temperature inside the ice making cell andthereby to maintain a predetermined range. This is because thesupercooled liquid has a characteristic in which the solidificationrapidly occurs from a time point at which the supercooling isterminated. In this case, the transparency of the ice may decrease.

In the process of solidifying the liquid, the controller of therefrigerator may control the supercooling release part to operate so asto reduce a degree of supercooling of the liquid if the time requiredfor reaching the specific temperature below the freezing point after thetemperature of the liquid reaches the freezing point is less than areference value. After reaching the freezing point, it is seen that thetemperature of the liquid is cooled below the freezing point as thesupercooling occurs, and no solidification occurs.

An example of the supercooling release part may include an electricalspark generating part. When the spark is supplied to the liquid, thedegree of supercooling of the liquid may be reduced. Another example ofthe supercooling release part may include a driver applying externalforce so that the liquid moves. The driver may allow the container tomove in at least one direction among X, Y, or Z axes or to rotate aboutat least one axis among X, Y, or Z axes. When kinetic energy is suppliedto the liquid, the degree of supercooling of the liquid may be reduced.Further another example of the supercooling release part may include apart supplying the liquid to the container. After supplying the liquidhaving a first volume less than that of the container, when apredetermined time has elapsed or the temperature of the liquid reachesa certain temperature below the freezing point, the controller of therefrigerator may control an amount of liquid to additionally supply theliquid having a second volume greater than the first volume. When theliquid is divided and supplied to the container as described above, theliquid supplied first may be solidified to act as freezing nucleus, andthus, the degree of supercooling of the liquid to be supplied may befurther reduced.

The more the degree of heat transfer of the container containing theliquid increase, the more the degree of supercooling of the liquid mayincrease. The more the degree of heat transfer of the containercontaining the liquid decrease, the more the degree of supercooling ofthe liquid may decrease.

The structure and method of heating the ice making cell in addition tothe heat transfer of the tray assembly may affect the making of thetransparent ice. As described above, the tray assembly may include afirst region and a second region, which define an outer circumferentialsurface of the ice making cell. For example, each of the first andsecond regions may be a portion of one tray assembly. For anotherexample, the first region may be a first tray assembly. The secondregion may be a second tray assembly.

The cold supplied to the ice making cell and the heat supplied to theice making cell have opposite properties. To increase the ice makingrate and/or improve the transparency of the ice, the design of thestructure and control of the cooler and the heater, the relationshipbetween the cooler and the tray assembly, and the relationship betweenthe heater and the tray assembly may be very important.

For a constant amount of cold supplied by the cooler and a constantamount of heat supplied by the heater, it may be advantageous for theheater to be arranged to locally heat the ice making cell so as toincrease the ice making rate of the refrigerator and/or to increase thetransparency of the ice. As the heat transmitted from the heater to theice making cell is transferred to an area other than the area on whichthe heater is disposed, the ice making rate may be improved. As theheater heats only a portion of the ice making cell, the heater may moveor collect the bubbles to an area adjacent to the heater in the icemaking cell, thereby increasing the transparency of the ice.

When the amount of heat supplied by the heater to the ice making cell islarge, the bubbles in the water may be moved or collected in the portionto which the heat is supplied, and thus, the made ice may increase intransparency. However, if the heat is uniformly supplied to the outercircumferential surface of the ice making cell, the ice making rate ofthe ice may decrease. Therefore, as the heater locally heats a portionof the ice making cell, it is possible to increase the transparency ofthe made ice and minimize the decrease of the ice making rate.

The heater may be disposed to contact one side of the tray assembly. Theheater may be disposed between the tray and the tray case. The heattransfer through the conduction may be advantageous for locally heatingthe ice making cell.

At least a portion of the other side at which the heater does notcontact the tray may be sealed with a heat insulation material. Such aconfiguration may reduce that the heat supplied from the heater istransferred toward the storage chamber.

The tray assembly may be configured so that the heat transfer from theheater toward the center of the ice making cell is greater than thattransfer from the heater in the circumference direction of the icemaking cell.

The heat transfer of the tray toward the center of the ice making cellin the tray may be greater than the that transfer from the tray case tothe storage chamber, or the thermal conductivity of the tray may begreater than that of the tray case. Such a configuration may induce theincrease in heat transmitted from the heater to the ice making cell viathe tray. In addition, it is possible to reduce the heat of the heateris transferred to the storage chamber via the tray case.

The heat transfer of the tray toward the center of the ice making cellin the tray may be less than that of the refrigerator case toward thestorage chamber from the outside of the refrigerator case (for example,an inner case or an outer case), or the thermal conductivity of the traymay be less than that of the refrigerator case. This is because the morethe heat or thermal conductivity of the tray increases, the more thesupercooling of the water accommodated in the tray may increase. Themore the degree of supercooling of the water increase, the more thewater may be rapidly solidified at the time point at which thesupercooling is released. In this case, a limitation may occur in whichthe transparency of the ice is not uniform or the transparencydecreases. In general, the case of the refrigerator may be made of ametal material including steel.

The heat transfer of the tray case in the direction from the storagechamber to the tray case may be greater than the that of the heatinsulation wall in the direction from the outer space of therefrigerator to the storage chamber, or the thermal conductivity of thetray case may be greater than that of the heat insulation wall (forexample, the insulation material disposed between the inner and outercases of the refrigerator). Here, the heat insulation wall may representa heat insulation wall that partitions the external space from thestorage chamber. If the degree of heat transfer of the tray case isequal to or greater than that of the heat insulation wall, the rate atwhich the ice making cell is cooled may be excessively reduced.

The first region may be configured to have a different degree of heattransfer in a direction along the outer circumferential surface. Thedegree of heat transfer of one portion of the first region may be lessthan that of the other portion of the first region. Such a configurationmay be assisted to reduce the heat transfer transferred through the trayassembly from the first region to the second region in the directionalong the outer circumferential surface.

The first and second regions defined to contact each other may beconfigured to have a different degree of heat transfer in the directionalong the outer circumferential surface. The degree of heat transfer ofone portion of the first region may be configured to be less than thedegree of heat transfer of one portion of the second region. Such aconfiguration may be assisted to reduce the heat transfer transferredthrough the tray assembly from the first region to the second region inthe direction along the outer circumferential surface. In anotheraspect, it may be advantageous to reduce the heat transferred from theheater to one portion of the first region to be transferred to the icemaking cell defined by the second region. As the heat transmitted to thesecond region is reduced, the heater may locally heat one portion of thefirst region. Thus, it may be possible to reduce the decrease in icemaking rate by the heating of the heater. In another aspect, the bubblesmay be moved or collected in the region in which the heater is locallyheated, thereby improving the transparency of the ice. The heater may bea transparent ice heater.

For example, a length of the heat transfer path from the first region tothe second region may be greater than that of the heat transfer path inthe direction from the first region to the outer circumferential surfacefrom the first region. For another example, in a thickness of the trayassembly in the direction of the outer circumferential surface of theice making cell from the center of the ice making cell, one portion ofthe first region may be thinner than the other of the first region orthinner than one portion of the second region. One portion of the firstregion may be a portion at which the tray case is not surrounded. Theother portion of the first region may be a portion that is surrounded bythe tray case. One portion of the second region may be a portion that issurrounded by the tray case. One portion of the first region may be aportion of the first region that defines the lowest end of the icemaking cell. The first region may include a tray and a tray case locallysurrounding the tray.

As described above, when the thickness of the first region is thin, theheat transfer in the direction of the center of the ice making cell mayincrease while reducing the heat transfer in the direction of the outercircumferential surface of the ice making cell. For this reason, the icemaking cell defined by the first region may be locally heated.

A minimum value of the thickness of one portion of the first region maybe less than that of the thickness of the other portion of the secondregion or less than that of one of the second region. A maximum value ofthe thickness of one portion of the first region may be less than thatof the thickness of the other portion of the first region or less thanthat of the thickness of one portion of the second region. When thethrough-hole is defined in the region, the minimum value represents theminimum value in the remaining regions except for the portion in whichthe through-hole is defined. An average value of the thickness of oneportion of the first region may be less than that of the thickness ofthe other portion of the first region or may be less than that of one ofthe thickness of the second region. The uniformity of the thickness ofone portion of the first region may be greater than that of thethickness of the other portion of the first region or greater than thatof one of the thickness of the second region.

For example, the tray assembly may include a first portion defining atleast a portion of the ice making cell and a second portion extendingfrom a predetermined point of the first portion. The first region may bedefined in the first portion. The second region may be defined in anadditional tray assembly that may contact the first portion. At least aportion of the second portion may extend in a direction away from theice making cell defined by the second region. In this case, the heattransmitted from the heater to the first region may be reduced frombeing transferred to the second region.

The structure and method of cooling the ice making cell in addition tothe degree of cold transfer of the tray assembly may affect the makingof the transparent ice. As described above, the tray assembly mayinclude a first region and a second region, which define an outercircumferential surface of the ice making cell. For example, each of thefirst and second regions may be a portion of one tray assembly. Foranother example, the first region may be a first tray assembly. Thesecond region may be a second tray assembly.

For a constant amount of cold supplied by the cooler and a constantamount of heat supplied by the heater, it may be advantageous toconfigure the cooler so that a portion of the ice making cell is moreintensively cooled to increase the ice making rate of the refrigeratorand/or increase the transparency of the ice. The more the cold suppliedto the ice making cell by the cooler increases, the more the ice makingrate may increase. However, as the cold is uniformly supplied to theouter circumferential surface of the ice making cell, the transparencyof the made ice may decrease. Therefore, as the cooler more intensivelycools a portion of the ice making cell, the bubbles may be moved orcollected to other regions of the ice making cell, thereby increasingthe transparency of the made ice and minimizing the decrease in icemaking rate.

The cooler may be configured so that the amount of cold supplied to thesecond region differs from that of cold supplied to the first region soas to allow the cooler to more intensively cool a portion of the icemaking cell. The amount of cold supplied to the second region by thecooler may be greater than that of cold supplied to the first region.

For example, the second region may be made of a metal material having ahigh cold transfer rate, and the first region may be made of a materialhaving a cold rate less than that of the metal.

For another example, to increase the degree of cold transfer transmittedfrom the storage chamber to the center of the ice making cell throughthe tray assembly, the second region may vary in degree of cold transfertoward the central direction. The degree of cold transfer of one portionof the second region may be greater than that of the other portion ofthe second region. A through-hole may be defined in one portion of thesecond region. At least a portion of the heat absorbing surface of thecooler may be disposed in the through-hole. A passage through which thecold air supplied from the cooler passes may be disposed in thethrough-hole. The one portion may be a portion that is not surrounded bythe tray case. The other portion may be a portion surrounded by the traycase. One portion of the second region may be a portion defining theuppermost portion of the ice making cell in the second region. Thesecond region may include a tray and a tray case locally surrounding thetray. As described above, when a portion of the tray assembly has a highcold transfer rate, the supercooling may occur in the tray assemblyhaving a high cold transfer rate. As described above, designs may beneeded to reduce the degree of the supercooling.

FIG. 2 is a side cross-sectional view illustrating a refrigerator inwhich an ice maker is installed.

As illustrated in FIG. 1(a), a refrigerator according to an embodimentof the present disclosure may include a plurality of doors 10, 20, and30 for opening and closing a storage chamber for food. The doors 10, 20,and 30 may include doors 10 and 20 for opening and closing the storagechamber in a rotating manner and a door 30 for opening and closing thestorage chamber in a sliding manner.

FIG. 1(b) is a cross-sectional view as viewed from the rear of therefrigerator. The refrigerator cabinet 14 may include a refrigeratingcompartment 18 and a freezing compartment 32. The refrigeratingcompartment 18 is disposed on the upper side, and the freezingcompartment 32 is disposed on the lower side, so that each storagechamber can be opened and closed individually by each door. Unlike thepresent embodiment, this embodiment is also applicable to a refrigeratorin which a freezing compartment is disposed on the upper side and arefrigerating compartment is disposed on the lower side.

The freezing compartment 32 may be divided into an upper space and alower space, and a drawer 40 capable of being withdrawn from andinserted into the lower space may be provided in the lower space.Although the freezing compartment 32 can be opened and closed by onedoor 30, the freezing compartment 32 may be provided to be separatedinto two spaces.

An ice maker 200 capable of manufacturing ice may be provided in theupper space of the freezing compartment 32.

An ice bin 600 in which ice produced by the ice maker 200 is fallen andstored may be provided under the ice maker 200. The user can take outthe ice bin 600 and use the ice stored in the ice bin 600. The ice bin600 may be mounted on an upper side of a horizontal wall separating theupper space and the lower space of the freezing compartment 32.

Referring to FIG. 2 , the cabinet 14 is provided with a duct 50 forsupplying cold air, which is an example of cold, to the ice maker 200.The duct 50 cools the ice maker 200 by discharging cold air suppliedfrom an evaporator through which the refrigerant compressed by thecompressor is evaporated. Ice may be generated in the ice maker 200 bythe cold air supplied to the ice maker 200.

In FIG. 2 , it is possible that the right side is the rear of therefrigerator and the left side is the front side of the refrigerator,that is, a part where a door is installed. At this time, the duct 50 maybe disposed at the rear of the cabinet 14 to discharge cold air towardthe front of the cabinet 14. The ice maker 200 is disposed in front ofthe duct 50.

The discharge port of the duct 50 is positioned on the ceiling of thefreezing compartment 32, and it is possible to discharge cold air to theupper side of the ice maker 200.

FIG. 3(a)-(b) is a perspective view of an ice maker according to anembodiment, FIG. 4(a)-(b) is a front view illustrating an ice maker, andFIG. 5 is an exploded perspective view of an ice maker.

FIGS. 3 a and 4 a are views including a bracket 220 for fixing the icemaker 200 to the freezing compartment 32, and FIGS. 3 b and 4 b areviews illustrating a state in which the bracket 220 is removed. Eachcomponent of the ice maker 200 may be provided inside or outside thebracket 220, and thus, the ice maker 200 may constitute one assembly.Accordingly, the ice maker 200 may be installed on the ceiling of thefreezing compartment 32.

A water supply part 240 is installed above the inner surface of thebracket 200. The water supply part 240 is provided with openings at theupper and lower sides, respectively, so that water supplied to the upperside of the water supply part 240 may be guided to the lower side of thewater supply part 240. The upper opening of the water supply part 240 islarger than the lower opening thereof, and thus, a discharge range ofwater guided downward through the water supply part 240 may be limited.

A water supply pipe through which water is supplied is installed abovethe water supply part 240, so that water is supplied to the water supplypart 240, and the supplied water may be moved downward. The water supplypart 240 may prevent the water discharged from the water supply pipefrom dropping from a high position, thereby preventing the water fromsplashing. Since the water supply part 240 is disposed below the watersupply pipe, the water may be guided downward without splashing up tothe water supply part 240, and an amount of splashing water may bereduced even if the water moves downward due to the lowered height.

The ice maker 200 may include a tray forming an ice making cell 320 a(see FIG. 18 ). The tray may include, for example, a first tray 320defining a portion of the ice making cell 320 a and a second tray 380defining another portion of the ice making cell 320 a.

The first tray 320 and the second tray 380 may define a plurality of icemaking cells 320 a in which a plurality of ice can be generated. A firstcell provided in the first tray 320 and a second cell provided in thesecond tray 380 may define a complete ice making cell 320 a.

The first tray 320 may have openings at upper and lower sides,respectively, so that water dropping from the upper side of the firsttray 320 can be moved downward.

A first tray supporter 340 may be disposed under the first tray 320. Thefirst tray supporter 340 has an opening formed to correspond to eachcell shape of the first tray 320 and thus may be coupled to the lowersurface of the first tray 320.

A first tray cover 300 may be coupled to an upper side of the first tray320. The outer appearance of the upper side of the first tray 320 may bemaintained. A first heater case 280 may be coupled to the first traycover 300. Alternatively, the first heater case 380 may be integrallyformed with the first tray cover 300.

The first heater case 280 is provided with a first heater (an iceseparation heater) to supply heat to the upper portion of the ice maker200. The first heater may be embedded in the heater case 280 orinstalled on one surface thereof.

The first tray cover 300 may be provided with a guide slot 302 inclinedat an upper side and vertically extending at a lower side. The guideslot 302 may be provided inside a member extending upward of the traycase 300.

The guide protrusion 262 of the first pusher 260 is inserted into theguide slot 302, so that the guide protrusion 262 may be guided along theguide slot 302. The first pusher 260 is provided with an extension part264 extending equal to the number of cells of each of the first tray320, so that ice positioned in each cell may be pushed out.

The guide protrusion 262 of the first pusher 260 is coupled to thepusher link 500. At this time, the guide protrusion 262 is rotatablycoupled to the pusher link 500 so that when the pusher link 500 moves,the first pusher 260 may also move along the guide slot 302.

A second tray cover 360 is provided on the upper side of the second tray380 so that the outer appearance of the second tray 380 can bemaintained. The second tray 380 has a shape protruding upward so that aplurality of cells constituting a space in which individual ice can begenerated are separated, and the second tray cover 360 can surround acell protruding upward.

A second tray supporter 400 is provided below the second tray 380 tomaintain a cell shape protruding downward from the second tray 380. Aspring 402 is provided on one side of the second tray supporter 400.

A second heater case 420 is provided under the second tray supporter400. A second heater (transparent ice heater) is provided in the secondheater case 420 to supply heat to the lower portion of the ice maker200.

The ice maker 200 is provided with a driver 480 that provides rotationalforce.

A through-hole 282 is formed in an extension part extending downward onone side of the first tray cover 300. A through-hole 404 is formed in anextension part extending to one side of the second tray supporter 400. Ashaft 440 penetrating the through-hole 282 and the through-hole 404together is provided, and rotation arms 460 are provided at both ends ofthe shaft 440, respectively. The shaft 440 may be rotated by receiving arotational force from the driver 480.

One end of the rotation arm 460 may be connected to one end of thespring 402, and thus, a position of the rotation arm 460 may move to aninitial value by restoring force when the spring 402 is tensioned.

A motor and a plurality of gears may be coupled to each other in thedriver 480.

A full ice detection lever 520 may be connected to the driver 480. Thefull ice detection lever 520 may also rotate by the rotational forceprovided by the driver 480.

The full ice detection lever 520 may have a ‘ c’ shape as a whole, andmay include a portion extending vertically at both ends and a portiondisposed horizontally connecting two portions extending vertically toeach other. One of the two vertically extending portions is coupled tothe driver 480 and the other is coupled to the bracket 220, so that thefull ice detection lever 520 can detect the ice stored in the ice bin600 while being rotated.

A second pusher 540 is provided on an inner lower surface of the bracket220. The second pusher 540 is provided with a coupling piece 542 coupledto the bracket 220 and a plurality of extension parts 544 installed onthe coupling piece 542. The plurality of extension parts 544 areprovided to be equal to the number of the plurality of cells provided inthe second tray 380, so that the extension part performs the function ofpushing so that the ice generated in the cells of the second tray 380can be separated from the second tray 380.

The first tray cover 300 and the second tray supporter 400 may berotatably coupled to each other with respect to the shaft 440 and may bedisposed so that an angle thereof is changed around the shaft 440.

Each of the first tray 320 and the second tray 380 is made of a materialthat is easily deformable, such as silicone, so that when pressed byeach pusher, it is instantly deformed so that the generated ice can beeasily separated from the tray.

FIGS. 6 to 11 are views illustrating a state in which some components ofthe ice maker are combined.

FIG. 6 is a view for explaining a state in which the bracket 220, thewater supply part 240, and the second pusher 540 are coupled. The secondpusher 540 is installed on the inner surface of the bracket 220, and theextension part of the second pusher 540 is disposed so that thedirection extending from the coupling piece 542 is not vertical butinclined downward.

FIG. 7 is a view illustrating a state in which the first heater case 280and the first tray cover 300 are coupled.

The first heater case 280 may be disposed such that a horizontal surfaceis spaced downward from the lower surface of the first tray cover 300.The first heater case 280 and the first tray cover 300 have an openingcorresponding to each cell of the first tray 320 so that water can passtherethrough, and the shape of each opening can form a shapecorresponding to each cell.

FIG. 8 is a view illustrating a state in which the first tray cover 300,the first tray 320, and the first tray supporter 340 are coupled.

The tray cover 340 is disposed between the first tray 320 and the firsttray cover 300.

The first tray cover 300, the first tray 320, and the tray cover 340 arecombined as a single module, so that the first tray cover 300, the firsttray 320, and the tray cover 340 may be disposed on the shaft 440 so asto be rotatable together with one member.

FIG. 9 is a view illustrating a state in which the second tray 380, thesecond tray cover 360, and the second tray supporter 400 are coupled.

With the second tray 380 interposed therebetween, the second tray cover360 is disposed on the upper side of the second tray, and the secondtray supporter 400 is disposed on the lower side of the second tray.

Each cell of the second tray 380 has a hemispherical shape to form alower portion of the spherical ice.

FIG. 10 is a view illustrating a state in which the second tray cover360, the second tray 380, the second tray supporter 400, and the secondheater case 420 are coupled.

The second heater case 420 may be disposed on a lower surface of thesecond tray case to fix a heater that supplies heat to the second tray380.

FIG. 11 is a view illustrating a state in which FIGS. 8 and 10 arecombined, and the rotary arm 460, the shaft 440, and the pusher link 500are combined.

One end of the rotation arm 460 is coupled to the shaft 440 and theother end thereof is coupled to the spring 402. One end of the pusherlink 500 is coupled to the first pusher 260 and the other end thereof isdisposed to be rotated with respect to the shaft 440.

FIG. 12 is a perspective view of a first tray viewed from belowaccording to an embodiment of the present disclosure, and FIG. 13 is across-sectional view of a first tray according to an embodiment of thepresent disclosure.

Referring to FIGS. 12 and 13 , the first tray 320 may define a firstcell 321 a that is a portion of the ice making cell 320 a.

The first tray 320 may include a first tray wall 321 defining a portionof the ice making cell 320 a.

For example, the first tray 320 may define a plurality of first cells321 a. For example, the plurality of first cells 321 a may be arrangedin a line. The plurality of first cells 321 a may be arranged in anX-axis direction based on FIG. 12 . For example, the first tray wall 321may define the plurality of first cells 321 a.

The first tray wall 321 may include a plurality of first cell walls 3211that respectively define the plurality of first cells 321 a, and aconnection wall 3212 connecting the plurality of first cell walls 3211to each other. The first tray wall 321 may be a wall extending in thevertical direction.

The first tray 320 may include an opening 324. The opening 324 maycommunicate with the first cell 321 a. The opening 324 may allow thecold air to be supplied to the first cell 321 a. The opening 324 mayallow water for making ice to be supplied to the first cell 321 a. Theopening 324 may provide a passage through which a portion of the firstpusher 260 passes. For example, in the ice separation process, a portionof the first pusher 260 may be inserted into the ice making cell 320 athrough the opening 234.

The first tray 320 may include a plurality of openings 324 correspondingto the plurality of first cells 321 a. One of the plurality of openings324 324 a may provide a passage of the cold air, a passage of the water,and a passage of the first pusher 260. In the ice making process, thebubbles may escape through the opening 324.

The first tray 320 may further include an auxiliary storage chamber 325communicating with the ice making cell 320 a. For example, the auxiliarystorage chamber 325 may store water overflowed from the ice making cell320 a. The ice expanded in a process of phase-changing the suppliedwater may be disposed in the auxiliary storage chamber 325. That is, theexpanded ice may pass through the opening 304 and be disposed in theauxiliary storage chamber 325. The auxiliary storage chamber 325 may bedefined by a storage chamber wall 325 a. The storage chamber wall 325 amay extend upwardly around the opening 324. The storage chamber wall 325a may have a cylindrical shape or a polygonal shape. Substantially, thefirst pusher 260 may pass through the opening 324 after passing throughthe storage chamber wall 325 a. The storage chamber wall 325 a maydefine the auxiliary storage chamber 325 and also reduce deformation ofthe periphery of the opening 324 in the process in which the firstpusher 260 passes through the opening 324 during the ice separationprocess.

The first tray 320 may include a first contact surface 322 c contactingthe second tray 380.

The first tray 320 may further include a first extension wall 327extending in the horizontal direction from the first tray wall 321. Forexample, the first extension wall 327 may extend in the horizontaldirection around an upper end of the first extension wall 327. One ormore first coupling holes 327 a may be provided in the first extensionwall 327. Although not limited, the plurality of first coupling holes327 a may be arranged in one or more axes of the X axis and the Y axis.

In this specification, the “central line” is a line passing through avolume center of the ice making cell 320 a or a center of gravity ofwater or ice in the ice making cell 320 a regardless of the axialdirection.

Meanwhile, referring to FIG. 13 , the first tray 320 may include a firstportion 322 that defines a portion of the ice making cell 320 a. Forexample, the first portion 322 may be a portion of the first tray wall321.

The first portion 322 may include a first cell surface 322 b (or anouter circumferential surface) defining the first cell 321 a. The firstportion 322 may include the opening 324. In addition, the first portion322 may include a heater accommodation part 321 c. An ice separationheater may be accommodated in the heater accommodation part 321 c. Thefirst portion 322 may be divided into a first region positioned close tothe second heater 430 in a Z-axis direction and a second regionpositioned away from the second heater 430. The first region may includethe first contact surface 322 c, and the second region may include theopening 324. The first portion 322 may be defined as an area between twodotted lines in FIG. 13 .

In a degree of deformation resistance from the center of the ice makingcell 320 a in the circumferential direction, at least a portion of theupper portion of the first portion 322 is greater than at least aportion of the lower portion. The degree of deformation resistance of atleast a portion of the upper portion of the first portion 322 is greaterthan that of the lowermost end of the first portion 322.

The upper and lower portions of the first portion 322 may be dividedbased on the extension direction of the central line C1 (or a verticalcenter line) in the Z axis direction in the ice making cell 320 a. Thelowermost end of the first portion 322 is the first contact surface 322c contacting the second tray 380.

The first tray 320 may further include a second portion 323 extendingfrom a predetermined point of the first portion 322. The predeterminedpoint of the first portion 322 may be one end of the first portion 322.Alternatively, the predetermined point of the first portion 322 may beone point of the first contact surface 322 c. A portion of the secondportion 323 may be defined by the first tray wall 321, and the otherportion of the second portion 323 may be defined by the first extensionwall 327. At least a portion of the second portion 323 may extend in adirection away from the transparent ice heater 430. At least a portionof the second portion 323 may extend upward from the first contactsurface 322 c. At least a portion of the second portion 323 may extendin a direction away from the central line C1. For example, the secondportion 323 may extend in both directions along the Y axis from thecentral line C1. The second portion 323 may be disposed at a positionhigher than or equal to the uppermost end of the ice making cell 320 a.The uppermost end of the ice making cell 320 a is a portion at which theopening 324 is defined.

The second portion 323 may include a first extension part 323 a and asecond extension part 323 b, which extend in different directions withrespect to the central line C1. The first tray wall 321 may include oneportion of the second extension part 323 b of each of the first portion322 and the second portion 323. The first extension wall 327 may includethe other portion of each of the first extension part 323 a and thesecond extension part 323 b.

Referring to FIG. 13 , the first extension part 323 a may be disposed atthe left side with respect to the central line C1, and the secondextension part 323 b may be disposed at the right side with respect tothe central line C1.

The first extension part 323 a and the second extension part 323 b mayhave different shapes based on the central line C1. The first extensionpart 323 a and the second extension part 323 b may be provided in anasymmetrical shape with respect to the central line C1.

A length of the second extension part 323 b in the Y-axis direction maybe greater than that of the first extension part 323 a. Therefore, whilethe ice is made and grown from the upper side in the ice making process,the degree of deformation resistance of the second extension part 323 bmay increase.

The second extension part 323 b may be disposed closer to the shaft 440that provides a center of rotation of the second tray assembly than thefirst extension part 323 a. In this embodiment, since the length of thesecond extension part 323 b in the Y-axis direction is greater than thatof the first extension part 323 a, the second tray 380 contacting thefirst tray 320 may increase in radius of rotation. When the rotationradius of the second tray assembly increases, centrifugal force of thesecond tray may increase. Thus, in the ice separation process,separating force for separating the ice from the second tray mayincrease to improve ice separation performance.

The thickness of the first tray wall 321 is minimized at a side of thefirst contact surface 322 c. At least a portion of the first tray wall321 may increase in thickness from the first contact surface 322 ctoward the upper side. Since the thickness of the first tray wall 321increases upward, a portion of the first portion 322 formed by the firsttray wall 321 serves as a deformation resistance reinforcement part (ora first deformation resistance reinforcement part). In addition, thesecond portion 323 extending outward from the first portion 322 alsoserves as a deformation resistance reinforcement part (or a seconddeformation resistance reinforcement part).

The deformation resistance reinforcement parts may be directly orindirectly supported by the bracket 220. The deformation resistancereinforcement part may be connected to the first tray case and supportedby the bracket 220 as an example. In this case, a portion of the firsttray case in contact with the inner deformation reinforcement portion ofthe first tray 320 may also serve as an inner deformation reinforcementportion. Such a deformation resistance reinforcement part may cause iceto be generated from the first cell 321 a formed by the first tray 320in a direction of the second cell 381 a formed by the second tray 380during the ice making process.

FIG. 14 is a perspective view of a second tray viewed from aboveaccording to an embodiment of the present disclosure, and FIG. 15 is across-sectional view taken along line 15-15 of FIG. 14 .

Referring to FIGS. 14 and 1 , the second tray 380 may define a secondcell 381 a which is another portion of the ice making cell 320 a.

The second tray 380 may include a second tray wall 381 defining aportion of the ice making cell 320 a.

For example, the second tray 380 may define a plurality of second cells381 a. For example, the plurality of second cells 381 a may be arrangedin a line. Referring to FIG. 14 , the plurality of second cells 381 amay be arranged in the X-axis direction. For example, the second traywall 381 may define the plurality of second cells 381 a.

The second tray 380 may include a circumferential wall 387 extendingalong a circumference of an upper end of the second tray wall 381. Thecircumferential wall 387 may be formed integrally with the second traywall 381 and may extend from an upper end of the second tray wall 381.For another example, the circumferential wall 387 may be providedseparately from the second tray wall 381 and disposed around the upperend of the second tray wall 381. In this case, the circumferential wall387 may contact the second tray wall 381 or be spaced apart from thethird tray wall 381. In any case, the circumferential wall 387 maysurround at least a portion of the first tray 320. If the second tray380 includes the circumferential wall 387, the second tray 380 maysurround the first tray 320. When the second tray 380 and thecircumferential wall 387 are provided separately from each other, thecircumferential wall 387 may be integrally formed with the second traycase or may be coupled to the second tray case. For example, one secondtray wall may define a plurality of second cells 381 a, and onecontinuous circumferential wall 387 may surround the first tray 250.

The circumferential wall 387 may include a first extension wall 387 bextending in the horizontal direction and a second extension wall 387 cextending in the vertical direction. The first extension wall 387 b maybe provided with one or more second coupling holes 387 a to be coupledto the second tray case. The plurality of second coupling holes 387 amay be arranged in at least one axis of the X axis or the Y axis.

The second tray 380 may include a second contact surface 382 ccontacting the first contact surface 322 c of the first tray 320. Thefirst contact surface 322 c and the second contact surface 382 c may behorizontal planes. Each of the first contact surface 322 c and thesecond contact surface 382 c may be provided in a ring shape. When theice making cell 320 a has a spherical shape, each of the first contactsurface 322 c and the second contact surface 382 c may have a circularring shape.

The second tray 380 may include a first portion 382 that defines atleast a portion of the ice making cell 320 a. For example, the firstportion 382 may be a portion or the whole of the second tray wall 381.

In this specification, the first portion 322 of the first tray 320 maybe referred to as a third portion so as to be distinguished from thefirst portion 382 of the second tray 380. Also, the second portion 323of the first tray 320 may be referred to as a fourth portion so as to bedistinguished from the second portion 383 of the second tray 380.

The first portion 382 may include a second cell surface 382 b (or anouter circumferential surface) defining the second cell 381 a of the icemaking cell 320 a. The first portion 382 may be defined as an areabetween two dotted lines in FIG. 8 . The uppermost end of the firstportion 382 is the second contact surface 382 c contacting the firsttray 320.

The second tray 380 may further include a second portion 383. The secondportion 383 may reduce transfer of heat, which is transferred from thesecond heater 430 to the second tray 380, to the ice making cell 320 adefined by the first tray 320. That is, the second portion 383 serves toallow the heat conduction path to move in a direction away from thefirst cell 321 a. The second portion 383 may be a portion or the wholeof the circumferential wall 387. The second portion 383 may extend froma predetermined point of the first portion 382. In the followingdescription, for example, the second portion 383 is connected to thefirst portion 382.

The predetermined point of the first portion 382 may be one end of thefirst portion 382. Alternatively, the predetermined point of the firstportion 382 may be one point of the second contact surface 382 c. Thesecond portion 383 may include the other end that does not contact oneend contacting the predetermined point of the first portion 382. Theother end of the second portion 383 may be disposed farther from thefirst cell 321 a than one end of the second portion 383.

At least a portion of the second portion 383 may extend in a directionaway from the first cell 321 a. At least a portion of the second portion383 may extend in a direction away from the second cell 381 a. At leasta portion of the second portion 383 may extend upward from the secondcontact surface 382 c. At least a portion of the second portion 383 mayextend horizontally in a direction away from the central line C1. Acenter of curvature of at least a portion of the second portion 383 maycoincide with a center of rotation of the shaft 440 which is connectedto the driver 480 to rotate.

The second portion 383 may include a first part 384 a extending from onepoint of the first portion 382. The second portion 383 may furtherinclude a second part 384 b extending in the same direction as theextending direction with the first part 384 a. Alternatively, the secondportion 383 may further include a third part 384 b extending in adirection different from the extending direction of the first part 384a. Alternatively, the second portion 383 may further include a secondpart 384 b and a third part 384 c branched from the first part 384 a.

For example, the first part 384 a may extend in the horizontal directionfrom the first part 382. A portion of the first part 384 a may bedisposed at a position higher than that of the second contact surface382 c. That is, the first part 384 a may include a horizontallyextension part and a vertically extension part. The first part 384 a mayfurther include a portion extending in the vertical direction from thepredetermined point. For example, a length of the third part 384 c maybe greater than that of the second part 384 b.

The extension direction of at least a portion of the first part 384 amay be the same as that of the second part 384 b. The extensiondirections of the second part 384 b and the third part 384 c may bedifferent from each other. The extension direction of the third part 384c may be different from that of the first part 384 a. The third part 384a may have a constant curvature based on the Y-Z cutting surface. Thatis, the same curvature radius of the third part 384 a may be constant inthe longitudinal direction. The curvature of the second part 384 b maybe zero. When the second part 384 b is not a straight line, thecurvature of the second part 384 b may be less than that of the thirdpart 384 a. The curvature radius of the second part 384 b may be greaterthan that of the third part 384 a.

At least a portion of the second portion 383 may be disposed at aposition higher than or equal to that of the uppermost end of the icemaking cell 320 a. In this case, since the heat conduction path definedby the second portion 383 is long, the heat transfer to the ice makingcell 320 a may be reduced. A length of the second portion 383 may begreater than the radius of the ice making cell 320 a. The second portion383 may extend up to a point higher than the center of rotation of theshaft 440. For example, the second portion 383 may extend up to a pointhigher than the uppermost end of the shaft 440.

The second portion 383 may include a first extension part 383 aextending from a first point of the first portion 382 and a secondextension part 383 b extending from a second point of the first portion382 so that transfer of the heat of the second heater 430 to the icemaking cell 320 a defined by the first tray 320 is reduced. For example,the first extension part 383 a and the second extension part 383 b mayextend in different directions with respect to the central line C1.

Referring to FIG. 15 , the first extension part 383 a may be disposed atthe left side with respect to the central line C1, and the secondextension part 383 b may be disposed at the right side with respect tothe central line C1. The first extension part 383 a and the secondextension part 383 b may have different shapes based on the central lineC1. The first extension part 383 a and the second extension part 383 bmay be provided in an asymmetrical shape with respect to the centralline C1. A length (horizontal length) of the second extension part 383 bin the Y-axis direction may be longer than the length (horizontallength) of the first extension part 383 a. The second extension part 383b may be disposed closer to the shaft 440 that provides a center ofrotation of the second tray assembly than the first extension part 383a.

In this embodiment, a length of the second extension part 383 b in theY-axis direction may be greater than that of the first extension part383 a. In this case, the heat conduction path may increase whilereducing the width of the bracket 220 relative to the space in which theice maker 200 is installed.

Since the length of the second extension part 383 b in the Y-axisdirection is greater than that of the first extension part 383 a, thesecond tray assembly including the second tray 380 contacting the firsttray 320 may increase in radius of rotation. When the rotation radius ofthe second tray assembly increases centrifugal force of the second trayassembly may increase. Thus, in the ice separation process, separatingforce for separating the ice from the second tray assembly may increaseto improve ice separation performance. The center of curvature of atleast a portion of the second extension part 383 b may be a center ofcurvature of the shaft 440 which is connected to the driver 480 torotate.

A distance between an upper portion of the first extension part 383 aand an upper portion of the second extension part 383 b may be greaterthan that between a lower portion of the first extension part 383 a anda lower portion of the second extension part 383 b with respect to theY-Z cutting surface passing through the central line C1. For example, adistance between the first extension part 383 a and the second extensionpart 383 b may increase upward. Each of the first extension part 383 aand the third extension part 383 b may include first to third parts 384a, 384 b, and 384 c. In another aspect, the third part 384 c may also bedescribed as including the first extension part 383 a and the secondextension part 383 b extending in different directions with respect tothe central line C1.

The first portion 382 may include a first region 382 d (see region A inFIG. 15 ) and a second region 382 e (remaining areas excluding regionA). The curvature of at least a portion of the first region 382 d may bedifferent from that of at least a portion of the second region 382 e.The first region 382 d may include the lowermost end of the ice makingcell 320 a. The second region 382 e may have a diameter greater thanthat of the first region 382 d. The first region 382 d and the secondregion 382 e may be divided vertically. The second heater 430 maycontact the first region 382 d. The first region 382 d may include aheater contact surface 382 g contacting the second heater 430. Theheater contact surface 382 g may be, for example, a horizontal plane.The heater contact surface 382 g may be disposed at a position higherthan that of the lowermost end of the first portion 382. The secondregion 382 e may include the second contact surface 382 c. The firstregion 382 d may have a shape recessed in a direction opposite to adirection in which ice is expanded in the ice making cell 320 a.

A distance from the center of the ice making cell 320 a to the secondregion 382 e may be less than that from the center of the ice makingcell 320 a to the portion at which the shape recessed in the first area382 d is disposed.

For example, the first region 382 d may include a pressing part 382 fthat is pressed by the second pusher 540 during the ice separationprocess. When pressing force of the second pusher 540 is applied to thepressing part 382 f, the pressing part 382 f is deformed, and thus, iceis separated from the first portion 382. When the pressing force appliedto the pressing part 382 f is removed, the pressing part 382 f mayreturn to its original shape. The central line C1 may pass through thefirst region 382 d. For example, the central line C1 may pass throughthe pressing part 382 f. The heater contact surface 382 g may bedisposed to surround the pressing unit 382 f. The heater contact surface382 g may be disposed at a position higher than that of the lowermostend of the pressing part 382 f.

At least a portion of the heater contact surface 382 g may be disposedto surround the central line C1. Accordingly, at least a portion of thetransparent ice heater 430 contacting the heater contact surface 382 gmay be disposed to surround the central line C1. Therefore, thetransparent ice heater 430 may be prevented from interfering with thesecond pusher 540 while the second pusher 540 presses the pressing unit382 f. A distance from the center of the ice making cell 320 a to thepressing part 382 f may be different from that from the center of theice making cell 320 a to the second region 382 e.

FIG. 16 is a top perspective view of a second tray supporter, and FIG.17 is a cross-sectional view taken along line 17-17 of FIG. 16 .

Referring to FIGS. 16 and 17 , the second tray supporter 400 may includea support body 407 on which a lower portion of the second tray 380 isseated. The support body 407 may include an accommodation space 406 a inwhich a portion of the second tray 380 is accommodated. Theaccommodation space 406 a may be defined corresponding to the firstportion 382 of the second tray 380, and a plurality of accommodationspaces 406 a may be provided.

The support body 407 may include a lower opening 406 b (or athrough-hole) through which a portion of the second pusher 540 passes.For example, three lower openings 406 b may be provided in the supportbody 407 to correspond to the three accommodation spaces 406 a. Aportion of the lower portion of the second tray 380 may be exposed bythe lower opening 406 b. At least a portion of the second tray 380 maybe disposed in the lower opening 406 b. A top surface 407 a of thesupport body 407 may extend in the horizontal direction.

The second tray supporter 400 may include a lower plate 401 that isstepped with the top surface 407 a of the support body 407. The lowerplate 401 may be disposed at a position higher than that of the topsurface 407 a of the support body 407. The lower plate 401 may include aplurality of coupling parts 401 a, 401 b, and 401 c to be coupled to thesecond tray cover 360. The second tray 380 may be inserted and coupledbetween the second tray cover 360 and the second tray supporter 400.

For example, the second tray 380 may be disposed below the second traycover 360, and the second tray 380 may be accommodated above the secondtray supporter 400.

The first extension wall 387 b of the second tray 380 may be coupled tothe coupling parts 361 a, 361 b, and 361 c of the second tray cover 360and the coupling parts 400 a, 401 b, and 401 c of the second traysupporter 400.

The second tray supporter 400 may further include a vertical extensionwall 405 extending vertically downward from an edge of the lower plate401. One surface of the vertical extension wall 405 may be provided witha pair of extension parts 403 coupled to the shaft 440 to allow thesecond tray 380 to rotate. The pair of extension parts 403 may be spacedapart from each other in the X-axis direction. Also, each of theextension parts 403 may further include a through-hole 404. The shaft440 may pass through the through-hole 404, and the extension part 281 ofthe first tray cover 300 may be disposed inside the pair of extensionparts 403.

The second tray supporter 400 may further include a spring coupling part402 a to which a spring 402 is coupled. The spring coupling part 402 amay provide a ring to be hooked with a lower end of the spring 402.

The second tray supporter 400 may further include a link connection part405 a to which the pusher link 500 is coupled. For example, the linkconnection part 405 a may protrude from the vertical extension wall 405in the X-axis direction.

Referring to FIG. 17 , the second tray supporter 400 may include a firstportion 411 supporting the second tray 380 defining at least a portionof the ice making cell 320 a. In FIG. 17 , the first portion 411 may bean area between two dotted lines. For example, the support body 407 maydefine the first portion 411.

The second tray supporter 400 may further include a second portion 413extending from a predetermined point of the first portion 411. Thesecond portion 413 may reduce transfer of heat, which is transfer fromthe second heater 430 to the second tray supporter 400, to the icemaking cell 320 a defined by the first tray 320. At least a portion ofthe second portion 413 may extend in a direction away from the firstcell 321 a defined by the first tray 320. The direction away from thefirst cell 321 may be a horizontal direction passing through the centerof the ice making cell 320 a. The direction away from the first cell 321may be a downward direction with respect to a horizontal line passingthrough the center of the ice making cell 320 a.

The second portion 413 may include a first part 414 a extending in thehorizontal direction from the predetermined point and a second part 414b extending in the same direction as the first part 414 a.

The second portion 413 may include a first part 414 a extending in thehorizontal direction from the predetermined point, and a third part 414c extending in a direction different from that of the first part 414 a.

The second portion 413 may include a first part 414 a extending in thehorizontal direction from the predetermined point, and a second part 414b and a third part 414 c, which are branched from the first part 414 a.

A top surface 407 a of the support body 407 may provide, for example,the first part 414 a. The first part 414 a may further include a fourthpart 414 d extending in the vertical line direction. The lower plate 401may provide, for example, the fourth part 414 d. The vertical extensionwall 405 may provide, for example, the third part 414 c.

A length of the third part 414 c may be greater than that of the secondpart 414 b. The second part 414 b may extend in the same direction asthe first part 414 a. The third part 414 c may extend in a directiondifferent from that of the first part 414 a. The second portion 413 maybe disposed at the same height as the lowermost end of the first cell321 a or extend up to a lower point. The second portion 413 may includea first extension part 413 a and a second extension part 413 b which aredisposed opposite to each other with respect to the center line CL1corresponding to the center line C1 of the ice making cell 320 a.

Referring to FIG. 17 , the first extension part 413 a may be disposed ata left side with respect to the center line CL1, and the secondextension part 413 b may be disposed at a right side with respect to thecenter line CL1.

The first extension part 413 a and the second extension part 413 b mayhave different shapes with respect to the center line CL1. The firstextension part 413 a and the second extension part 413 b may have shapesthat are asymmetrical to each other with respect to the center line CL1.

A length of the second extension part 413 b may be greater than that ofthe first extension part 413 a in the horizontal direction. That is, alength of the thermal conductivity of the second extension 413 b isgreater than that of the first extension part 413 a. The secondextension part 413 b may be disposed closer to the shaft 440 thatprovides a center of rotation of the second tray assembly than the firstextension part 413 a.

In this embodiment, since the length of the second extension part 413 bin the Y-axis direction is greater than that of the first extension part413 a, the second tray assembly including the second tray 380 contactingthe first tray 320 may increase in radius of rotation.

A center of curvature of at least a portion of the second extension part413 a may coincide with a center of rotation of the shaft 440 which isconnected to the driver 480 to rotate.

The first extension part 413 a may include a portion 414 e extendingupwardly with respect to the horizontal line. The portion 414 e maysurround, for example, a portion of the second tray 380.

In another aspect, the second tray supporter 400 may include a firstregion 415 a including the lower opening 406 b and a second region 415 bhaving a shape corresponding to the ice making cell 320 a to support thesecond tray 380. For example, the first region 415 a and the secondregion 415 b may be divided vertically. In FIG. 11 , for example, thefirst region 415 a and the second region 415 b are divided by adashed-dotted line. The first region 415 a may support the second tray380. The controller controls the ice maker to allow the second pusher540 to move from a first point outside the ice making cell 320 a to asecond point inside the second tray supporter 400 via the lower opening406 b. A degree of deformation resistance of the second tray supporter400 may be greater than that of the second tray 380. A degree ofrestoration of the second tray supporter 400 may be less than that ofthe second tray 380.

In another aspect, the second tray supporter 400 includes a first region415 a including a lower opening 406 b and a second region 415 b disposedfarther from the second heater 430 than the first region 415 a.

FIG. 18 is a cross-sectional view taken along line 18-18 of FIG. 3(a),and FIG. 19 is a view illustrating a state in which the second tray ismoved to the water supply position in FIG. 18 .

Referring to FIGS. 18 and 19 , the ice maker 200 may include a firsttray assembly 201 and a second tray assembly 211, which are connected toeach other.

The first tray assembly 201 may include a first portion forming at leasta portion of the ice making cell 320 a and a second portion connectedfrom the first portion to a predetermined point.

The first portion of the first tray assembly 201 may include a firstportion 322 of the first tray 320, and the second portion of the firsttray assembly 201 may include a second portion 322 of the first tray320. Accordingly, the first tray assembly 201 includes the deformationresistance reinforcement parts of the first tray 320.

The first tray assembly 201 may include a first region and a secondregion positioned further from the second heater 430 than the firstregion. The first region of the first tray assembly 201 may include afirst region of the first tray 320, and the second region of the firsttray assembly 201 may include a second region of the first tray 320.

The second tray assembly 211 may include a first portion 212 defining atleast a portion of the ice making cell 320 a and a second portion 213extending from a predetermined point of the first portion 212. Thesecond portion 213 may reduce transfer of heat from the second heater430 to the ice making cell 320 a defined by the first tray assembly 201.The first portion 212 may be an area disposed between two dotted linesin FIG. 12 .

The predetermined point of the first portion 212 may be an end of thefirst portion 212 or a point at which the first tray assembly 201 andthe second tray assembly 211 meet each other. At least a portion of thefirst portion 212 may extend in a direction away from the ice makingcell 320 a defined by the first tray assembly 201. At least two portionsof the second portion 213 may be branched to reduce heat transfer in thedirection extending to the second portion 213. A portion of the secondportion 213 may extend in the horizontal direction passing through thecenter of the ice making cell 320 a. A portion of the second portion 213may extend in an upward direction with respect to a horizontal linepassing through the center of the ice making chamber 320 a.

The second portion 213 includes a first part 213 c extending in thehorizontal direction passing through the center of the ice making cell320 a, a second part 213 d extending upward with respect to thehorizontal line passing through the center of the ice making cell 320 a,a third part 213 e extending downward.

The first portion 212 may have different degree of heat transfer in adirection along the outer circumferential surface of the ice making cell320 a to reduce transfer of heat, which is transferred from the secondheater 430 to the second tray assembly 211, to the ice making cell 320 adefined by the first tray assembly 201. The second heater 430 may bedisposed to heat both sides of the first portion 212 with respect to thelowermost end of the first portion 212.

The first portion 212 may include a first region 214 a and a secondregion 214 b. In FIG. 18 , the first region 214 a and the second region214 b are divided by a dashed-dotted line. The second region 214 b maybe a region defined above the first region 214 a. The degree of heattransfer of the second region 214 b may be greater than that of thefirst region 214 a.

The first region 214 a may include a portion at which the second heater430 is disposed. That is, the first region 214 a may include the secondheater 430.

The lowermost end 214 a 1 of the ice making cell 320 a in the firstregion 214 a may have a heat transfer rate less than that of the otherportion of the first region 214 a. The distance from the center of theice making cell 320 a to the outer circumferential surface is greater inthe second region 214 b than in the first region 214 a.

The second region 214 b may include a portion in which the first trayassembly 201 and the second tray assembly 211 contact each other. Thefirst region 214 a may provide a portion of the ice making cell 320 a.The second region 214 b may provide the other portion of the ice makingcell 320 a. The second region 214 b may be disposed farther from thesecond heater 430 than the first region 214 a.

Part of the first region 214 a may have the degree of heat transfer lessthan that of the other part of the first region 214 a to reduce transferof heat, which is transferred from the second heater 430 to the firstregion 314 a, to the ice making cell 320 a defined by the second region214 b.

To make ice in the direction from the ice making cell 320 a defined bythe first region 214 a to the ice making cell 320 a defined by thesecond region 214 b, a portion of the first region 214 a may have adegree of deformation resistance less than that of the other portion ofthe first region 214 a and a degree of restoration greater than that ofthe other portion of the first region 214 a.

A portion of the first region 214 a may be thinner than the otherportion of the first region 214 a in the thickness direction from thecenter of the ice making cell 320 a to the outer circumferential surfacedirection of the ice making cell 320 a.

For example, the first region 214 a may include a second tray casesurrounding at least a portion of the second tray 380 and at least aportion of the second tray 380. For example, the first region 214 a mayinclude the pressing part 382 f of the second tray 380. The rotationcenter C4 may be disposed closer to the second pusher 540 than to theice making cell 320 a. The second portion 213 may include a firstextension part 213 a and a second extension part 323 b, which aredisposed at sides opposite to each other with respect to the centralline C1.

The first extension part 213 a may be disposed at a left side of thecenter line C1 in FIG. 18 , and the second extension part 213 b may bedisposed at a right side of the center line C1 in FIG. 41 . The watersupply part 240 may be disposed close to the first extension part 213 a.The first tray assembly 301 may include a pair of guide slots 302, andthe water supply part 240 may be disposed in a region between the pairof guide slots 302.

The ice maker 200 according to this embodiment may be designed such thatthe position of the second tray 380 is different from a water supplyposition and an ice making position. In FIG. 19 , as an example, a watersupply position of the second tray 380 is illustrated. For example, inthe water supply position as illustrated in FIG. 19 , at least a portionof the first contact surface 322 c of the first tray 320 and the secondcontact surface 382 c of the second tray 380 may be spaced apart. InFIG. 19 , for example, it is illustrated that all of the first contactsurfaces 322 c are spaced apart from all of the second contact surfaces382 c. Accordingly, in the water supply position, the first contactsurface 322 c may be inclined to form a predetermined angle with thesecond contact surface 382 c.

Although not limited, in the water supply position, the first contactsurface 322 c may be substantially horizontal, and the second contactsurface 382 c may be disposed to be inclined below the first tray 320with respect to the first contact surface 322 c.

Meanwhile, in the ice making position (see FIG. 18 ), the second contactsurface 382 c may contact at least a portion of the first contactsurface 322 c. The angle formed between the second contact surface 382 cof the second tray 380 and the first contact surface 322 c of the firsttray 320 at the ice making position is smaller than the angle formedbetween the second contact surface 382 c of the second tray 380 and thefirst contact surface 322 c of the first tray 320 at the water supplyposition.

In the ice making position, all of the first contact surface 322 c maycontact the second contact surface 382 c. In the ice making position,the second contact surface 382 c and the first contact surface 322 c maybe disposed to be substantially horizontal.

In this embodiment, the reason why the water supply position and the icemaking position of the second tray 380 are different is that in a casein which the ice maker 200 includes a plurality of ice making cells 320a, water is to be uniformly distributed to the plurality of ice makingcells 320 a without forming water passage for communication betweenrespective ice making cells 320 a in he first tray 320 and/or the secondtray 380.

If the ice maker 200 includes the plurality of ice making cells 320 a,when a water passage is formed in the first tray 320 and/or the secondtray 380, the water supplied to the ice maker 200 is distributed to theplurality of ice making cells 320 a along the water passage. However, ina state in which the water is distributed to the plurality of ice makingcells 320 a, water exists in the water passage, and when ice isgenerated in this state, ice generated in the ice making cell 320 a isconnected by ice generated in the water passage portion. In this case,there is a possibility that the ice will be attached to each other evenafter the ice separation is completed, and even if the ice is separatedfrom each other, some of the plurality of ice contain ice generated inthe water passage portion, so there is a problem that the shape of theice is different from the shape of the ice making cell.

However, as in the present embodiment, in a case in which the secondtray 380 is spaced apart from the first tray 320 at the water supplyposition, the water dropped to the second tray 380 may be uniformlydistribured to the plurality of second cells 381 a of the second tray380.

The water supply part 240 may supply water to one of the plurality ofopenings 324. In this case, the water supplied through the one opening324 drops into the second tray 380 after passing through the first tray320. During the water supply process, water may drop into any one secondcell 381 a of the plurality of second cells 381 a of the second tray380. Water supplied to one second cell 381 a overflows from one secondcell 381 a.

In the present embodiment, since the second contact surface 382 c of thesecond tray 380 is spaced apart from the first contact surface 322 c ofthe first tray 320, the water overflowing from the second cell 381 amoves to another adjacent second cell 381 a along the second contactsurface 382 c of the second tray 380. Accordingly, the plurality ofsecond cells 381 a of the second tray 380 may be filled with water.

In addition, in a state in which the water supply is completed, aportion of the water supplied is filled in the second cell 381 a, andanother part of the water supplied may be filled in the space betweenthe first tray 320 and the second tray 380. When the second tray 380moves from the water supply position to the ice making position, waterin the space between the first tray 320 and the second tray 380 may beuniformly distributed to the plurality of first cells 321 a.

Meanwhile, when a water passage is formed in the first tray 320 and/orthe second tray 380, ice generated in the ice making cell 320 a is alsogenerated in the water passage portion.

In this case, in order to generate transparent ice, if the controller ofthe refrigerator controls one or more of the cooling power of the coolerand the heating amount of the second heater 430 to be varied accordingto the mass per unit height of water in the ice making cell 320 a, inthe portion in which the water passage is formed, one or more of thecooling power of the cooler and the heating amount of the second heater430 is controlled to rapidly vary several times or more.

This is because the mass per unit height of water is rapidly increasedseveral times or more in the portion where the water passage is formed.In this case, reliability problems of parts may occur, and expensiveparts with large widths of the maximum and minimum outputs can be used,which may be disadvantageous in terms of power consumption and cost ofthe parts. As a result, the present disclosure may require a techniquerelated to the above-described ice making position to generatetransparent ice.

FIGS. 20(a)-(d) and 21(a)-(b) are views for explaining a process ofsupplying water to the ice maker.

FIG. 20(a)-(d) is a view illustrating a process of supplying water whileviewing the ice maker from the side, and FIG. 21(a)-(b) is a viewillustrating a process of supplying water while viewing the ice makerfrom the front.

As illustrated in FIG. 20(a), the first tray 320 and the second tray 380are disposed in a state of being separated from each other, and then, asillustrated in FIG. 20(b), the second tray 380 is rotated in the reversedirection toward the tray 320. At this time, although a part of thefirst tray 320 and the second tray 380 overlap, the first tray 320 andthe second tray 380 are completely engaged so that the inner spacethereof does not form a spherical shape.

As illustrated in FIG. 20(c), water is supplied into the tray throughthe water supply part 240. Since the first tray 320 and the second tray380 are not fully engaged, some of the water passes out of the firsttray 320. However, since the second tray 380 includes a peripheral wallformed to surround the upper side of the first tray 320 to be spacedapart, water does not overflow from the second tray 380.

FIG. 21 is a view for specifically explaining FIG. 20(c), wherein thestate changes in the order of FIG. 21(a) and FIG. 21(b).

As illustrated in FIG. 20(c), when water is supplied to the first tray320 and the second tray 380 through the water supply part 240, the watersupply part 240 is disposed to be biased toward one side of the tray.

That is, the first tray 320 is provided with a plurality of cells 321 a1, 321 a 2, 321 a 3 for generating a plurality of independent ices. Thesecond tray 380 is also provided with a plurality of cells 381 a 1, 381a 2, 381 a 3 for generating a plurality of independent ices. As thecells disposed in the first tray 320 and the cells disposed in thesecond tray 380 are combined, one spherical ice may be generated.

In FIG. 21 , the first tray 320 and the second tray 380 do notcompletely contact as in FIG. 20(c) and the front sides of the firsttray and the second tray are separated from each other, so that thewater in each cell can move between the cells.

As illustrated in FIG. 21(a), when water is supplied to the upper sideof the cells 321 a 1 and 381 a 1 positioned on one side, the water movesinto the inside of the cells 321 a 1 and 381 a 1. At this time, whenwater overflows from the lower cell 381 a 1, water may be moved to theadjacent cells 321 a 2 and 381 a 2. Since the plurality of cells are notcompletely isolated from each other, when the water level in the cellrises above a certain level, each cell can be filled with the waterwhile the water moves to the surrounding cells.

In a case in which predetermined water is supplied from a water supplyvalve disposed in a water supply pipe provided outside the ice maker200, a flow path may be closed so that water is no longer supplied tothe ice maker 200.

FIG. 22(a)-(c) is a diagram illustrating a process of ice beingseparated in an ice maker.

Referring to FIG. 22 , when the second tray 380 is further rotated inthe reverse direction in FIG. 20(c), as illustrated in FIG. 21(a), thefirst tray 320 may be disposed so as to form a spherical shape togetherwith the second tray 380 and the cell. The second tray 380 and the firsttray 320 are completely combined to each other and disposed so thatwater may be separated in each cell.

When cold air is supplied for a predetermined time in the state of FIG.22(a), ice is generated in the ice making cell of the tray. While thewater is changed to ice by cold air, the first tray 320 and the secondtray 380 are engaged with each other as illustrated in FIG. 22(a) tomaintain a state in which water does not move.

When ice is generated in the ice making cell of the tray, as illustratedin FIG. 22(b), in a state in which the first tray 320 is stopped, thesecond tray 380 is rotated in the forward direction.

At this time, since the ice has own weight thereof, the ice may dropfrom the first tray 320. Since the first pusher 260 presses the icewhile descending, it is possible to prevent ice from being attached tothe first tray 320.

Since the second tray 380 supports the lower portion of the ice, even ifthe second tray 380 is moved in the forward direction, the state inwhich the ice is mounted on the second tray 380 is maintained. Asillustrated in FIG. 22(b), even in a state in which the second tray 380is rotated to exceed a vertical angle, there may be a case where ice isattached to the second tray 380.

Therefore, in this embodiment, the second pusher 540 deforms thepressing part of the second tray 380, and as the second tray 380 isdeformed, the attachment force between the ice and the second tray 380is weakened and thus ice may fall from the second tray 380.

After the ice has fallen from the second tray 380, although notillustrated in FIG. 22 , the ice may fall into the ice bin 600.

FIG. 23 is a control block diagram according to an embodiment.

Referring to FIG. 23 , in an embodiment of the present disclosure, atray temperature sensor 700 for measuring the temperature of the firsttray 320 or the second tray 380 is provided.

The temperature measured by the tray temperature sensor 700 istransmitted to the controller 800.

The controller 800 may control the driver 480 (or the motor part) torotate the motor in the driver 480.

The controller 800 may control a water supply valve 740 that opens andcloses a flow path of water supplied to the ice maker 200 so that wateris supplied to the ice maker 200 or the supply of water to the ice makeris stopped.

When the driver 480 is operated, the second tray 380 or the full icedetection lever 520 may be rotated.

A second heater 430 may be installed in the second heater case 420. Thesecond heater 430 may supply heat to the second tray 380. Since thesecond heater 430 is disposed under the second tray 380, it may bereferred to as a lower heater.

A second heater 290 may be provided in the first heater case 280. Thefirst heater 290 may supply heat to the first tray 320. Since the firstheater 290 is disposed above the second heater 430, the first heater 290may be referred to as an upper heater.

Power is supplied to the first heater 290 and the second heater 430according to a command of the controller 800 to generate heat.

FIG. 24 is a view for explaining an example of a heater applied to anembodiment.

The second heater 430 illustrated in FIG. 24 is installed in the secondheater case 420. The second heater 430 may be installed on the uppersurface of the second heater case 420. The second heater 430 may beexposed above the second heater case 420.

Of course, the second heater 430 may be installed to be embedded in thesecond heater case 420.

The second heater 430 may include a straight part 432 and a curved part434. Both the straight part 432 and the curved part 434 are formed ofelements capable of generating heat. When a current flows through thestraight part 432 and the curved part 434, heat may be entirelygenerated by resistance.

The straight part 432 means a portion extending in a linear direction.The curved part 434 may have a trajectory of a generally semicirculararc in the form of opening outward and then closing inward. The secondheater 430 may be formed in the form of a single line and may have ashape in which the straight part 432 and the curved part 434 arealternately disposed to form a symmetrical shape to each other.

In the second heater 430, the curved part 434 may be disposed at aposition where each cell of the second tray 380 is disposed. Since thecell has a hemispherical shape and the flat cross section is circular,the two curved parts 434 facing each other are disposed to form aportion of a circular arc.

The second heater 430 may have an approximately circular cross section.

In FIG. 24 , only the second heater 430 has been described, but theabove description applies equally to the first heater 290. That is, thefirst heater 290 may also be provided with a curved part and a straightpart alternately like the second heater 430. However, unlike the secondheater 430, the first heater 290 is installed in the first heater case280 and is disposed above the tray.

FIG. 25(a)-(b) is a view schematically illustrating a state in which thesecond heater contacts the second tray.

In FIG. 25 , a cross-sectional view of one cell among the plurality ofcells 381 a of the second tray 380 is illustrated. The cells of thesecond tray 380 may have a substantially hemispherical shape, so thatwhen the cells are filled with water and water is turned into ice, thehemispherical shape may be maintained by the second tray 380. The upperhemispherical shape is implemented by the first tray 320.

A heater contact part 382 g is provided on the outer surface of eachcell of the second tray 380. The heater contact part 382 g may form asurface to which the second heater 430 can contact, as illustrated inFIG. 25(b).

The heater contact part 382 g forms a flat surface, so that the secondheater 430 may stably contact. In addition, since the second heater 430includes a curved part of an approximately circular shape, the heatercontact part 382 g is disposed so that a certain portion overlaps by thesecond heater 430, so that the second heater 430 can compress the heatercontact part 382 g. Since the second heater 430 is installed in acompressed manner, the second tray 380 may remain in contact with thesecond heater 430 even if a tolerance occurs during assembly and massproduction.

FIG. 26 is a view for explaining the operation of the second tray andthe heater.

Referring to FIG. 26 , a portion indicated by a dotted line indicates astate before the second pusher 540 presses the second tray 380, and aportion indicated by a solid line indicates a state in which the secondpusher 540 presses the second tray 380.

Since the second heater 430 contacts the second tray 380 but is notfixed to be attached, regardless of a state in which the second pusher540 presses or does not press the second tray 380, the second heater isplaced in the same location.

The second heater 430 is fixed to the second heater case 420, and inFIG. 26 , the second heater case 420 is omitted for convenience ofdescription.

The second tray 380 may be made of a silicon material. When an externalforce is applied, the second tray 380 may be deformed around a portionto which the force is applied. Therefore, in a case in which ice isfrozen in the cell of the second tray 380, when the second pusher 540deforms the second tray 380, the ice may be separated from the secondtray 380.

Specifically, the second heater 430 is compressed to the second tray 380and maintains a state of being in contact with the second tray 380.Then, in order to separate the ice frozen in the second tray 380 fromthe second tray 380, the second pusher 540 may press the second tray380. As the second tray 380 is deformed, the second heater 430 fallsfrom the second tray 380 without contacting. This is because the secondheater 430 is not integrally attached to the second tray 380. Therefore,compared to the method in which the second heater 430 is attached to thesecond tray 380, even if the second tray 380 is deformed to separate icefrom the second tray 420, it is possible to prevent damage such asdisconnection of the second heater 430 from occurring.

The present embodiment can be applied equally to a tray capable ofgenerating spherical ice, as well as an ice maker generatingsquare-shaped ice. That is, in addition to the form in which the upperside and the second tray are provided together in the ice maker, it ispossible to equally apply the concept described above to the ice makerprovided with only the second tray. In this embodiment, when the heaterapplies heat to the tray, that is, when ice is generated, the heater andthe tray come into contact with each other. On the other hand, when iceis separated from the tray, that is, when ice is separated, since theheater and the tray can be separated, even if the shape of the tray isdeformed, the heater is not damaged.

In the present embodiment, a brief description will be given of aprocess in which ice is finally made after water is supplied to the icemaker and ice is made.

As illustrated in FIG. 20(b), the second tray 380 is disposed so as notto be horizontal, but inclined at a predetermined angle. At this time,the second tray 380 may be rotated about 6 degrees relative to thehorizontal plane to maintain an inclined state.

As illustrated in FIG. 20(c), since the second tray 380 is inclined whenwater is supplied to the tray, water supplied to one cell may spread toother cells.

On the other hand, when the ice making is in progress after the watersupply is completed, the second tray 380 is rotated so that the secondcontact surface 382 c of the second tray 380 is parallel to thehorizontal surface as illustrated in FIG. 22(a). At this time, the firsttray 320 and the second tray 380 are completely coupled to each other sothat each cell is disposed to form a spherical shape.

When ice is made, the second heater 430 may be turned on so that ice cangrow from the top of the ice making cell.

That is, power may be supplied to the second heater 430 so that heat isgenerated by the second heater 430. The second heater 430 is positionedcloser to a lower end than an upper end of the ice making cell. On theother hand, on the upper side of the ice making cell, the temperature islowered by the cold air supplied from the duct. That is, the upper sidehas a low temperature while the lower side has a high temperature basedon the ice making cell, so that a condition in which ice is generated onthe upper side is satisfied.

The temperature of the upper side of the ice making cell is low, so theice is getting bigger, but the bubbles contained in the water are notcollected by the ice, and the bubbles are gradually discharged downwardso that the bubbles are not collected by the ice.

Therefore, almost no bubbles exist in the generated ice, and transparentice can be manufactured. In this embodiment, the ice grows from theupper side to the lower side, because the temperature is maintained atthe lower side than the upper side. Therefore, the direction of icegeneration is kept constant, so that the ice may become transparent.

When the temperature of the tray is measured by the tray temperaturesensor 700 and the temperature falls below a predetermined temperature,it may be determined that ice generation is completed as illustrated inFIG. 22(a). Accordingly, it is determined that ice can be provided tothe user, and the first heater 290 may be operated.

The first heater 290 supplies heat after ice generation is completed,thereby creating conditions in which ice is easily separated from thetray. The first heater 290 applies heat to the first tray 320 so thatice is separated from the first tray 320.

When heat is applied by the first heater 290, the portion of the firsttray 320 in contact with ice melts and is converted into water, and theice is separated from the first tray 320.

The tray temperature sensor 700 measures the temperature of the tray,and when the temperature of the tray rises by a predeterminedtemperature, it may be determined that the portion of the ice in contactwith the first tray 320 has melted. In this case, when the second tray380 is rotated in the forward direction as illustrated in FIGS. 22(b)and 22(c), ice is separated from the first tray 320 and mounted on thesecond tray 380. In this case, since ice may not be separated from thefirst tray 320, the first pusher 260 pushes the ice from the first tray320. Since an opening is provided above each of the first tray 320, thefirst pusher 260 may be disposed in each cell through the opening. Theupper side of the first tray 320 is exposed to outside air throughrespective openings, and cold air supplied through the duct may beguided to the inside of the first tray 320 through the opening.Therefore, as the water contacts the cold air, the temperature of thewater decreases and ice may be formed.

As the rotation angle of the second tray 380 increases, the secondpusher 540 presses the second tray 380 to deform the second tray 380.Ice may be separated from the second tray 380, dropped downward, andfinally stored in the ice bin.

FIG. 27 is a view for explaining a process of generating ice, and FIG.28 is a view for explaining a second tray temperature and a heatertemperature.

A heater can be disposed at the bottom of the tray to make transparentice. If the output of the heater is constantly input, the ice makingspeed is high at the beginning of ice making, that is, when ice is madeat the top, while the ice making speed is low when ice making isperformed at the lower end, so relatively opaque ice is generated in theupper part.

In addition, if the heating amount of the heater increases to make theupper part transparent, the rate at which ice is generated on the upperpart may be slowed to generate transparent ice, but since the icegeneration time at the low end portion is lengthened, the ice makingtime is lengthened and the amount of ice making may be reduced.

If the heating amount of the heater is constantly controlled whilemaking ice, there is a difference between the rate at which ice is madeat the top and the rate at which ice is made at the bottom.

Therefore, in this embodiment, transparent ice can be generated bychanging the heating amount of the heater.

In order to manufacture transparent ice, it is necessary to adjust thefreezing speed from the top to the lower end through the second heater430 installed at the lower end. If it freezes quickly, air scratchesoccur, creating opaque ice. Therefore, in order to generate transparentice, it has to be slowly frozen using a heater so that air is nottrapped in the ice.

Since cold air is supplied from the upper side, when the upper icegrows, it grows rapidly and the lower part freezes slowly compared tothe upper part. If the heater is heated according to the ice growth rateon the upper side, the ice making time is prolonged because it freezestoo slowly when the ice on the lower side is generated, and when theheater is heated according to the lower freezing rate, ice with anopaque upper side is generated.

Therefore, in this embodiment, in order to make transparent ice whilesecuring the ice making speed, the heater output may be varied instages.

The ice generated by the ice maker according to the present embodimentcan be divided into three regions as a whole. As illustrated in FIG. 27, the spherical ice can be divided into a first region A1, a secondregion A2, and a third region A3 as a whole.

The first region A1 may mean a portion in which transparent ice isgenerated even without heater control. The first region is a portionwhere water meets the first tray 320 and is a portion in which sphericalice is initially generated. Since the portion meeting the first tray 320initially has a similar temperature distribution to the first tray 320,the temperature may be relatively low.

The second region A2 is not adjacent to the first tray 320 but is aportion which is positioned within a cell formed in the first tray 320.Since the second region is a portion disposed close to the center of thespherical ice, it is difficult for air to escape, and thus transparencymay be difficult to be maintained. The second region is a portionsurrounded by the first region and may mean a region similar to atriangular pyramid having a triangular cross section based on thedrawing.

The third region A3 is a space in which ice is generated in a cellprovided in the second tray 380. Since the third region has ahemispherical shape as a whole, but is a portion disposed close to thesecond heater 430, heat generated by the second heater 430 can be easilytransferred.

In this embodiment, when ice is generated in the portion correspondingto the third region A3, the heating amount generated by the heater ischanged. Furthermore, even when ice is generated in the portioncorresponding to the third region A3, since the ice generating conditionin the third region is different from the ice generating condition inthe first region A1 or in the second region A2, the heating amount ofthe second heater 430 is changed. That is, by changing the temperatureof the second heater 430, the speed at which ice freezes may beadjusted.

In FIG. 28 , a dotted line indicates the temperature measured by thetray temperature sensor 700, and a solid line indicates the temperatureof the second heater 430. Since the temperature of the second heater 430varies according to the output of the second heater 430, the variabletemperature of the second heater 430 described below may mean thevariable output of the second heater 430.

Water is supplied to the ice maker 200, and the second heater 430 is notdriven for a predetermined time. That is, since the second heater 430does not generate heat, the tray is not heated. However, when water issupplied, since the temperature of the water is higher than thetemperature of the freezing compartment in which the ice maker islocated, the temperature of the tray measured by the tray temperaturesensor 700 may be temporarily increased.

When the water supply is completed and a predetermined time elapses, thesecond heater 430 is driven. In this case, the second heater 430 may bedriven with a first output for a first set time. In this case, ice maybe generated in the first region A1. At this time, the second heater 430generates heat in the first temperature range. For example, the firstset time may mean approximately 45 minutes, and the first output maymean 4.5 W.

In addition, after the first set time has elapsed, the second heater 430may be driven with the second output for the second set time. At thistime, ice may be generated in the second region A2. At this time, thesecond heater 430 generates heat in the second temperature range. Forexample, the second set time may mean approximately 195 minutes, and thesecond output may mean 5.5 W.

After the second set time has elapsed, the second heater 430 may bedriven with a third output for a third set time. In this case, ice maybe generated in the third region A3. At this time, the second heater 430generates heat in the third temperature range. For example, the thirdset time may mean approximately 198 minutes, and the third output maymean 4 W.

The average value of the first temperature range is smaller than theaverage value of the second temperature range. The average value of thesecond temperature range is greater than the average value of the thirdtemperature range. The average value of the third temperature range issmaller than the average value of the first temperature range.

In this embodiment, water supply is started and the heater waits afterthe heater is turned off for a predetermined time, first heating isperformed, when the predetermined temperature reaches, second heating isperformed, in addition, when the next temperature reaches, third heatingis performed, and finally the heater may be controlled in a method ofturning off the heater.

Comparing the first temperature range, the second temperature range, andthe third temperature range, the second temperature range is thehighest, the first temperature range is the next highest, and the thirdtemperature range is the lowest. While ice is generated in the firstregion A1, the second heater 430 is driven in the second highesttemperature range.

While ice is frozen in the first region A1, there are many paths throughwhich air contained in water can escape, so that the possibility of airbeing collected is relatively small. Accordingly, transparent ice may begenerated in the first region even if the second heater 430 is notdriven at the highest temperature.

In the second area A2, since a path through which air can escape isrelatively small, and a cross-sectional area of ice frozen based on aspherical shape is large, the second heater 430 is driven at the highesttemperature.

In the third area A3, ice is generated at a location relatively close tothe second heater 430, and since heat generated from the second heater430 can be easily transferred, the second heater 430 is driven at thelowest temperature.

The time when the second heater 430 is driven with the first output maybe shorter than a time when the second heater 430 is driven with thesecond output or the third output. When driven by the first output,since ice is generated in the first region A1, the amount of icegenerated is relatively small compared to the second region A2 or thethird region A3. Therefore, the driving time with the first output issmaller than that of the second output or the third output, so that theoverall ice freezing speed can be kept constant.

As illustrated in FIG. 28 , when the temperature measured by the traytemperature sensor 700 during ice making after the water supply isfinished is considered, it can be seen that the temperature graduallydecreases from about 0 degrees to −8 degrees with a constant slope. Asthe temperature of the tray decreases at a constant rate, ice generatedin the tray may also grow at a constant rate. Therefore, the aircontained in the water is not trapped in the ice and is discharged tothe outside, so that transparent ice can be manufactured.

It is also possible to control the heater by dividing the heater intomore stages than in this embodiment.

Referring to FIG. 22 , a process of separating ice from the first trayand the second tray after the spherical ice is generated will bedescribed.

In this embodiment, heat may be supplied to the first tray 320 by usingthe first heater 290 installed on the first tray 320. When heat issupplied from the first heater 290 provided in the first tray 320, whilethe outer surface of the ice formed in the first tray 320 (the surfacemeeting the first tray 320) is heated, the ice is changed into water.

Ice may be separated from the first tray 320. Of course, the firstpusher 260 may allow ice to be separated from the first tray 320, sothat reliability of ice separation may be improved.

In addition, ice may be pressed from below by the second pusher 540 tobe separated from the second tray 380.

In order to separate the ice after the ice is completed, the firstheater 290 disposed above the first tray 320 is first driven in thestate of FIG. 22(a). The temperature of the first tray 320 may increaseby supplying heat from the first heater 290. The first heater 290 isdriven until the tray temperature measured by the tray temperaturesensor 700 increases or a predetermined time elapses.

While the first heater 290 is driven, the first tray 320 and the secondtray 380 are not moved, and a state in which ice is meshed with thefirst tray 320 and the second tray 380 is maintained. That is, while iceis filled in the ice making cell formed in the first tray 320 and thesecond tray 380, the first heater 290 is driven to heat the first tray320 and ice attached to the first tray 320.

After driving the first heater 290, when a predetermined time elapses orwhen a predetermined temperature is reached, it is determined that thesurface of the ice in contact with the first tray 320 has melted, andthe second tray 380 is rotated by the set angle.

At this time, the rotation angle is not a angle illustrated in FIG.22(b), but it is preferable that the rotation angle is approximately 10to 45 degrees positioned in the middle of FIG. 22(a) (a state in whichthe second tray is not rotated) and FIG. 22(b) (the second tray isrotated by 90 degrees or more). In this case, the set angle is an angleat which ice may not escape from the second tray 380. In a state inwhich the second tray 380 is rotated by the set angle, ice that mayremain in the first tray 320 may fall to the second tray 380.

Meanwhile, even if the first heater 290 is driven in a state in whichthe second tray 380 is rotated by a set angle (approximately 10 to 45degrees), since the ice located in the second tray 380 is at a distancefrom the first heater 290 and is in a state of being separated from thefirst tray 320, excessive melting of the ice may be prevented.

In this embodiment, even in a state in which the second tray 380 isrotated by a set angle and thus there is a high possibility that ice isseparated from the first tray 320. the first heater 290 is driven andthus ice can be further heated if ice is not separated from the firsttray 320, That is, when ice is kept in contact with the first tray 320,reliability that ice is separated from the tray 320 may be improvedwhile the surface of the first tray 320 and the ice in contact with eachother is changed to water by heat supplied from the first heater 290.

However, if the ice is already separated from the first tray 320, sincethe heat supplied from the first heater 290 is difficult to betransferred to the ice by the conduction method, it is possible toprevent the already separated ice from melting by the first heater 290.

When the first heater 290 is driven and a set time elapses in a state inwhich the second tray 380 is rotated by a set angle from the first tray320, the driving of the first heater 290 is stopped.

Even after the first heater 290 is turned off, after waiting for apredetermined period of time (approximately 1 to 10 minutes), the secondtray 380 is rotated to a position (ice separation position) pressurizedby the second pusher 540 as illustrated in FIG. 22(c). That is, even ina state in which heat is not supplied by the first heater 290, when thesecond tray 380 is rotated by a set angle, ice can be separated by thesecond pusher 540 from the second tray 380.

FIG. 29(a)-(d) is a view for explaining an operation in a case in whichfull ice is not detected in an embodiment of the present disclosure, andFIG. 30 is a view for explaining an operation in a case in which fullice is detected in an embodiment of the present disclosure.

A conventional technique for detecting full ice in an ice maker thatmanufactures ice has a method for operating the full ice detection partup and down. A twisting type ice maker, which is a method of dischargingice from the tray by twisting the tray after supplying water to thetray, detects whether ice is full by moving the lever up and down. Thatis, as the lever moves down, it can detect whether there is ice. In acase in which the lever is sufficiently lowered, it is determined thatice is not sufficiently stored in the lower portion of the tray, and ina case in which the lever is not sufficiently lowered, it is determinedthat ice is stored in the lower portion of the tray. Therefore, the iceis discharged from the tray.

However, in this embodiment, since the tray is composed of a first trayand a second tray, the space occupied by the tray becomes larger thanthat of the twisting ice maker. Therefore, the space in which ice binsfor storing ice can be located is also reduced. In addition, in the caseof using a lever that moves up and down to determine whether ice isstored, there is a problem that ice located under the lever can bedetected, but ice located on the side outside the lower part of thelever cannot be detected.

FIG. 29(a)-(d) is a view illustrating an operation in a case in whichthere is a space for additional ice storage in the ice bin 600 (in acase in which full ice is not detected).

As illustrated in FIG. 29(a), after the ice is completed, the firstheater 290 is driven before the second tray 380 is rotated, so that thesurface of ice which contacts the first tray 320 melts and ice may beseparated from the first tray 320.

In a case in which the first heater 290 is driven for a predeterminedtime, the second tray 380 starts to rotate as illustrated in FIG. 29(b).At this time, the first pusher 260 penetrates the upper side of thefirst tray 320 and presses the ice to separate the ice from the firsttray 320.

Even in a case in which ice is not sufficiently separated from the firsttray 320 by the first heater 290, the ice may be reliably separated bythe first pusher 260.

As the second tray 380 is rotated, the full ice detection lever 520 isalso rotated. If the movement of the full ice detection lever 520 is notdisturbed by ice while the full ice detection lever 520 is rotated tothe position of FIG. 29(b), the second tray 380 is continuously rotatedin a clockwise direction so that ice can separated from the second tray380 while the second tray 380 is further rotated as illustrated in FIG.29(c).

At this time, the full ice detection lever 520 maintains a stopped stateat the position of FIG. 29(b). That is, initially, the second tray 380and the full ice detection lever 520 are rotated together, but in astate in which the full ice detection lever 520 is sufficiently rotated,the full ice detection lever 520 is not rotated and only the second tray380 is further rotated. The angle at which the full ice detection lever520 is rotated may be approximately an angle disposed vertically withrespect to the bottom surface of the ice bin 600, that is, a horizontalsurface. That is, the full ice detection lever 520 is rotated in aclockwise direction up to an approximately vertical angle with respectto a horizontal plane, and the angle at which the rotation of the fullice detection lever 520 is stopped is preferably a position at which thefull ice detection lever can be lowered to the lowest level while oneend of the full ice detection lever 520 is rotated.

The full ice detection lever 520 and the second tray 380 may be rotatedtogether or individually by the rotational force provided by the driver480. The full ice detection lever 520 and the second tray 380 areconnected to one rotation shaft provided by the driver 480 and may berotated while drawing one rotation radius.

Since the second tray 380 is rotated by a rotation shaft, a trajectoryin which the second tray 380 moves must be secured unlike when thesecond tray 380 is stopped. In addition, since the full ice detectionlever 520 also detects full ice in a rotational manner, the full icedetection lever 520 must be rotated to a height lower than that of thesecond tray 380.

Therefore, the length of the full ice detection lever 520 extends longerthan one end of the second tray 380, so that whether ice exists in theice bin 600 should be detected. That is, the full ice detection lever520 is connected to a rotation shaft provided in the driver 480 and thusmay be rotated.

The full ice detection lever 520 starts to rotate when the second tray380 is rotated, and since the second tray 380 is rotated after the iceis completed, whether ice is full can be detected after the ice iscompleted.

The full ice detection lever 520 is a swing type that rotates about arotation shaft rather than a vertical movement method, so that whetherice is stored in the ice bin 600 may be detected while moving along arotation trajectory.

After the ice is moved from the second tray 380 to the ice bin 600, asillustrated in FIG. 29(d), the second tray 380 rotates counterclockwiseagain. Before the full ice detection lever 520 is rotated to theposition illustrated in FIG. 29(b), the full ice detection lever 520maintains a stopped state. When the second tray 380 reaches the rotationangle as illustrated in FIG. 29(b), the ice detection lever 520 rotatescounterclockwise with the second tray 380 and can return to the positionof FIG. 29(a) which is the initial position.

As illustrated in FIG. 30(a), since ice is stored in the lower portionof the ice bin 600, in a situation in which it is difficult toadditionally store ice in the ice bin 600, it is determined that ice isfull and the ice is not moved to the ice bin 600.

First, in a case in which ice is completed, the first heater 290 isdriven to separate the ice from the first tray 320. This process is thesame as the content described in FIG. 29(a), so a repeated descriptionwill be omitted.

Subsequently, as illustrated in FIG. 30(a), the second tray 380 and thefull ice detection lever 520 are rotated clockwise together to detectwhether the ice bin 600 is full.

Before the full ice detection lever 520 is rotated to FIG. 29(b), asillustrated in FIG. 30(b), in a case in which the full ice detectionlever 520 touches ice and cannot be rotated any more, it is determinedthat the ice bin 600 is filled with ice.

Accordingly, the full ice detection lever 520 and the second tray 380are not rotated any more and are returned to a water supply position(FIG. 30(c)) where water is supplied to the tray. At this time, thesecond tray 380 and the full ice detection lever 520 are rotatedtogether to return to the original position thereof.

As illustrated in FIG. 30(d), after a predetermined time has elapsed,whether the ice is filled is detected again. That is, by rotating thesecond tray 380 and the full ice detection lever 520 clockwise again,whether the ice bin 600 is full is detected.

FIG. 31(a)-(c) is a view for explaining an operation in a case in whichfull ice is not detected in another embodiment of the presentdisclosure, and FIG. 32(a)-(c) is a view for explaining an operation ina case in which full ice is detected in another embodiment of thepresent disclosure.

In another embodiment, unlike FIGS. 29 and 30 , the thickness of thefull ice detection lever is wider. It is provided in the form of a barthicker than a wire, so that ice contained in the ice bin 600 can bedetected.

In FIGS. 31 and 32 , unlike the previous embodiment, an inclined plate610 is disposed on the bottom of the ice bin 600. The inclined plate 610is disposed to have a slope of a predetermined angle on the bottom ofthe ice bin 600 and serves to guide ice stored in the ice bin 600 tocollect in a predetermined direction.

The inclined plate 610 is disposed such that a portion close to thesecond tray 380 has a high height and a portion far from the second tray380 has a low height. Accordingly, ice separated from the second tray380 and falling into the ice bin 600 is guided away from the second tray380.

The description will be made with reference to FIGS. 31 and 32 , but thecontent overlapping with the description of the previous embodiment willbe omitted, and the differences will be mainly described.

As illustrated in FIG. 31 , when the full ice detection lever 530 andthe second tray 380 are rotated, if ice is not detected by the full icedetection lever 530 by the full ice detection lever 530, it isdetermined that the ice bin 600 has not been filled. Accordingly, asillustrated in FIG. 31(b), the full ice detection lever 530 returns tothe initial position while rotating in a counterclockwise direction, andthe second tray 380 is further rotated to fall ice to the ice bin 600and to move.

The ice collected in the ice bin 600 is collected at a position awayfrom the second tray 380 due to a height difference between the inclinedplate 610.

As illustrated in FIG. 32 , when the full ice detection lever 530 andthe second tray 380 are rotated, if ice is not detected by the full icedetection lever 530, it is determined that the ice bin 600 is full withice. Therefore, as illustrated in FIG. 32(a), when the full icedetection lever 530 touches ice, the full ice detection lever 530 andthe second tray 380 are no longer clockwise and rotate counterclockwiseagain to return to the original position.

After a predetermined time has elapsed, the full ice detection lever 530is rotated again to detect ice in the ice bin 600. The reason why thefull ice detection lever 530 is rotated again is because a userwithdraws ice from the ice bin 600 or an error in detecting whether theice is full in the ice bin 600 may occur.

The inclined plate 610 applied in another embodiment may be applied inthe same manner to the previous embodiment. In the case of makingspherical ice, if the depth of the ice bin 600 is long, ice may bedamaged when the ice falls from the tray to the ice bin 600. Therefore,the thickness of the ice bin 600 can store spherical ice, but it isbetter to have a shallow depth if possible. When this condition issatisfied, since the depth of the ice bin 600 is inevitably shallow, astorage space for ice may be insufficient. Therefore, the ice stored inthe ice bin 600 is sequentially moved to a predetermined place, so thatthe ice can be spread evenly in the ice bin 600 so that the ice storagespace may be widely used.

FIG. 33 is a block diagram of a refrigerator according to anotherembodiment of the present disclosure, and FIG. 34 is a flowchartillustrating a process of generating ice in an ice maker according toanother embodiment of the present disclosure.

FIG. 35 is a cross-sectional view of an ice maker in a water supplystate, FIG. 36 is a cross-sectional view of an ice maker in an icemaking state, FIG. 37 is a cross-sectional view of an ice maker in astate in which ice making is completed, FIG. 38 is a cross-sectionalview of an ice maker in an initial state of ice separation, and FIG. 39is a cross-sectional view of an ice maker in a state in which iceseparation is completed.

Referring to FIGS. 33 to 39 , the refrigerator according to the presentembodiment may further include a controller 800 that controls the firstheater 290 and the second heater 430.

The refrigerator may further include a defrost heater 710 for defrostingan evaporator for supplying cold air to the freezing compartment 32.

The refrigerator may further include a door opening detection part 730that detects an opening of a door for opening and closing a storagechamber (for example, a freezing compartment) in which the ice maker 200is installed.

For example, when the ice maker 200 is provided in the freezingcompartment 32, the door opening detection part 730 may detect theopening of the freezing compartment door.

The refrigerator may further include an input part 720 configured to setand change a target temperature of a storage chamber in which the icemaker 200 is provided.

For example, target temperatures of the refrigerating compartment 18 andthe freezing compartment 32 may be set and changed through the inputpart 720.

The controller 800 may adjust the output of the second heater 430 duringthe ice making process.

In the ice making process, when a defrost is started, a door opening andclosing is detected, or a change in a target temperature of the storagechamber is detected, the current output of the second heater may bemaintained or changed in response thereto.

Specific output control of the second heater 430 will be described laterwith reference to the drawings.

In order to generate ice in the ice maker 200, first, the second tray380 is moved to a water supply position (S1).

As an example, while the second tray 380 is moved to an ice separationposition to be described later, the controller 800 may control thedriver 400 to rotate the second tray 380 in a reverse direction.

At the water supply position of the second tray 380, the second contactsurface 382 c of the second tray 380 is spaced apart from the firstcontact surface 322 c of the first tray 320.

In the present embodiment, the direction in which the second tray 380 isrotated (counterclockwise based on the drawing) for ice separation isreferred to as a forward direction, and the opposite direction(clockwise) is referred to as a reverse direction.

At the water supply position of the second tray 380, water supply starts(S2).

When the water supply is completed, a portion of the water supplied maybe filled in the second tray 380, and another portion of the watersupplied may be filled in the space between the first tray 320 and thesecond tray 380.

In the present embodiment, the second tray 380 does not have, forexample, a channel for mutual communication between the three secondcells 381 a.

As described above, even if there is no channel for water movement inthe second tray 380, the second contact surface 382 c of the second tray380 is spaced apart from the first contact surface 322 c of the firsttray 320. Therefore, when a specific second cell is filled with waterduring the water supply process, water may flow to another second cellalong the second contact surface 382 c of the second tray 380.Accordingly, the plurality of second cells 381 a of the second tray 380may be filled with water.

When the water supply is completed, the second tray 380 is moved to theice making position.

For example, as illustrated in FIG. 36 , the controller 800 may controlthe driver 400 so that the second tray 380 is rotated in a reversedirection.

When the second tray 380 is rotated in the reverse direction, the secondcontact surface 382 c of the second tray 380 becomes close to the firstcontact surface 322 c of the first tray 320. Then, the water between thesecond contact surface 382 c of the second tray 380 and the firstcontact surface 322 c of the first tray 320 is divided and distributedinside each of the plurality of first cells 321 a. When the uppersurface 251 e of the second tray 380 and the lower surface 151 e of thefirst tray 320 are completely in close contact, the upper chamber 152 isfilled with water.

The position of the second tray 380 in a state in which the secondcontact surface 382 c of the second tray 380 and the first contactsurface 322 c of the first tray 320 are in close contact can be referredto as the ice making position.

In the state in which the second tray assembly 211 moves to the icemaking position, ice making is started (S4).

During ice making, since the pressing force of water (or the expansionforce of water) is less than the force for deforming the pressingportion 382 f of the second tray 380, the pressing portion 382 f is notdeformed and maintains the original shape thereof.

After the start of ice making, the controller 800 determines whether theturn-on condition of the second heater 430 is satisfied (S5).

That is, in the case of the present embodiment, the second heater 430 isnot turned on immediately after ice making starts, and the second heater430 is turned on only when the turn-on condition of the second heater430 is satisfied (S6).

Specifically, generally, the water supplied to the ice making cell 320 amay be water having normal temperature or water having a temperaturelower than the normal temperature. The temperature of the water suppliedis higher than a freezing point of water. Thus, after the water supply,the temperature of the water is lowered by the cold air, and when thetemperature of the water reaches the freezing point of the water, thewater is changed into ice.

In the present embodiment, the second heater 430 is not turned on untilthe water changes into ice. If the second heater 430 is turned on beforereaching the freezing point of water in the ice making cell 320 a, therate at which the temperature of water reaches the freezing point isslowed by the heat of the second heater 430, and as a result, icegeneration rate slows down. That is, the second heater is unnecessarilyoperated regardless of the transparency of the ice. Accordingly,according to the present embodiment, when the turn-on condition of thesecond heater 430 is satisfied, the second heater 430 is turned on, sothat power cannot be consumed due to unnecessary operation of the secondheater 430.

In the present embodiment, when the temperature sensed by thetemperature sensor 700 reaches the turn-on reference temperature, thecontroller 800 determines that the turn-on condition of the secondheater 430 is satisfied. For example, the turn-on reference temperatureis a temperature for determining that water has started to freeze in theuppermost side (opening side) of the ice making cell 320 a.

In this embodiment, since the remaining portion of the ice making cell320 a other than the aperture is blocked by the first tray 320 and thesecond tray 380 and thus the water in the ice making cell 320 a directlycontacts the cold air through the opening 324, ice starts to begenerated from the uppermost side of the ice making cell 320 a where theopening 324 is located.

In this embodiment, the temperature sensor 700 does not directly detectthe temperature of ice, and the temperature sensor 700 contacts thefirst tray 320 to detect the temperature of the first tray 320.

By this structural disposition, in order to determine that ice hasstarted to be generated in the ice making cell 320 a based on thetemperature sensed by the temperature sensor 700, the turn-on referencetemperature may be set to a sub-zero temperature.

That is, in a case in which the temperature sensed by the temperaturesensor 700 reaches the turn-on reference temperature, since the turn-onreference temperature is a sub-zero temperature, the ice temperature ofthe ice making cell 320 a is a sub-zero temperature and is lower thanthe turn-on reference temperature. Therefore, it can be indirectlydetermined that ice is generated in the ice making cell 320 a.

When the second heater 430 is turned on, heat from the second heater 430is transferred to the second tray 380. Therefore, when ice making isperformed in a state in which the second heater 430 is turned on, heatis supplied to the water contained in the second cell 381 a within theice making cell 320 a and thus ice is generated from above in the icemaking cell 320 a.

In this embodiment, since ice is generated from the top in the icemaking cell 320 a, the bubbles in the ice making cell 320 a movedownward. Since the density of water is greater than the density of ice,bubbles in the water can easily move downwards and collect downwards.

Since the ice making cell 320 a is formed in a spherical shape, thehorizontal cross-sectional area is different for each height of the icemaking cell 320 a. Assuming that the same amount of cool air is suppliedto the ice making cell 320 a, if the output of the second heater 430 isthe same, the horizontal cross-sectional area is different for eachheight of the ice making cell 320 a and thus the rate at which ice isgenerated may vary depending on the height. In other words, the heightat which ice is generated per unit time is not uniform. In this case,bubbles in the water are included in the ice without moving downward,and the ice becomes opaque.

Accordingly, in the present embodiment, the controller 800 controls theoutput of the second heater 430 by varying according to the height atwhich ice is generated in the ice making cell 320 a (S7).

The horizontal cross-sectional area of ice increases as it goes from thetop to the bottom, then reaches a maximum at the boundary between thefirst tray 320 and the second tray 380, and then decreases to thebottom. In response to the change in the horizontal cross-sectional areaaccording to the height, the controller 800 may vary the output of thesecond heater 430. Variable control of the output of the second heater430 will be described later with reference to the drawings.

Ice is in contact with the upper surface of the pressing portion 382 fof the second tray 380 while ice is continuously generated from the topto the bottom in the ice making cell 320 a. When ice is continuouslygenerated in this state, the pressing portion 382 f is pressed anddeformed as illustrated in FIG. 37 , and when ice making is completed,ice in a sphere shape may be generated.

The controller 800 may determine whether ice making is completed basedon the temperature sensed by the temperature sensor 700 (S8).

When it is determined that ice making is completed, the controller 800turns off the second heater 430 (S9).

In the present embodiment, since the distance between the temperaturesensor 700 and each ice making cell 320 a is different, in order todetermine that ice generation has been completed in all ice making cells320 a, the controller 800 can start the ice separation after apredetermined time has elapsed from the time it is determined that icemaking is completed.

When the ice making is completed, the controller 800 operates the firstheater 290 to remove the ice (S10).

When the first heater 290 is turned on, heat from the first heater 290is transferred to the first tray 320 so that ice may be separated fromthe surface (inner surface) of the first tray 320. In addition, the heatof the first heater 290 is transferred to the contact surface betweenthe first tray 320 and the second tray 380, so that the portion betweenthe first contact surface 322 c of the first tray 320 and the secondcontact surface 382 c of the second tray 380 is in a state of beingcapable of being separated.

When the first heater 290 is operated for a set time, the controller 800turns off the first heater 290. The controller 800 operates the driver400 so that the second tray 380 is rotated in a forward direction (S11).

As illustrated in FIG. 38 , when the second tray 380 is rotated in theforward direction, the second tray 380 is separated from the first tray320 and spaced apart from the first tray 320.

The rotational force of the second tray 380 is transmitted to the firstpusher 260 by the connection part 350. Then, the first pusher 260 islowered, so that the first pusher 260 can press the ice.

During the ice separation process, ice may be separated from the firsttray 320 before the first pusher 260 presses the ice. That is, ice maybe separated from the surface of the first tray 320 by the heat of thefirst heater 290. In this case, the ice may be rotated together with thesecond tray 380 in a state of being supported by the second tray 380.

Alternatively, even if the heat of the first heater 290 is applied tothe first tray 320, there may be a case where ice is not separated fromthe surface of the first tray 320. Accordingly, when the second tray 380is rotated in the forward direction, ice may be separated from thesecond tray 380 in a state in which the ice is in close contact with thefirst tray 320.

In this state, in the process of rotating the second tray 380, the firstpusher 260 passing through the opening 324 presses the ice in closecontact with the first tray 320, so that the ice may be separated fromthe first tray 320. Ice separated from the first tray 320 may besupported by the second tray 380 again.

In a case in which ice is rotated together with the second tray 380 in astate in which ice is supported by the second tray 380, even if noexternal force is applied to the second tray 380, the ice can beseparated from the tray 380 by the own weight thereof.

If, in the process of rotating the second tray 380, even if ice is notseparated from the second tray 380 by the own weight thereof, when thesecond tray 380 is pressed by the second pusher 540 as illustrated inFIG. 37 , ice may be separated from the second tray 380.

Specifically, in a process in which the second tray 380 is rotated, thesecond tray 380 comes into contact with the second pusher 540. When thesecond tray 380 is continuously rotated in the forward direction, thesecond pusher 540 presses the second tray 380 so that the second tray380 is deformed, and the pressing force of the second pusher 540 istransferred to the ice so that the ice may be separated from the surfaceof the second tray 380. Ice separated from the surface of the secondtray 380 may fall downward and be stored in the ice bin.

After the ice is separated from the second tray 380, the controller 800controls the driver 400 to rotate the second tray 380 in the reversedirection.

When the second pusher 540 is spaced apart from the second tray 380 in aprocess in which the second tray 380 is rotated in the reversedirection, the deformed second tray 380 may be restored to the originalshape thereof.

In the process of rotating the second tray 380 in the reverse direction,a rotational force is transferred to the first pusher 260, so that thefirst pusher 260 rises, and the first pusher 260 is removed from the icemaking cell 320 a. When the second tray 380 reaches the water supplyposition, the driver 400 is stopped, and water supply starts again.

FIG. 40 is a diagram for explaining an output of a second heater foreach height of ice generated in an ice making cell. FIG. 40(a)illustrates that the spherical ice making cell is divided into aplurality of sections by height, and FIG. 40(b) illustrates the outputamount of the second heater for each height section of the ice makingcell.

In this embodiment, as an example, a case in which a spherical icemaking cell (or ice spacing) having a diameter of 50 mm is divided into9 sections (A section to I section) at 6 mm interval (referenceinterval) is described, and it should be noted that there is no limit tothe diameter of the ice making cell (or the diameter of ice) and thenumber of divided sections.

FIG. 41 is a graph illustrating a temperature sensed by a temperaturesensor and an output amount of a second heater during a water supply andice making process, and FIG. 42 is a view illustrating step by step aprocess in which ice is generated for each ice height section.

In FIG. 42 , I is the generated ice and W is water.

Referring to FIGS. 40 and 41 , in a case in which the ice making cellsare divided by the reference interval, the height of each dividedsection is the same between section A and section H, and section I islower than the rest of sections. Of course, depending on the diameter ofthe ice making cell (or the diameter of ice) and the number of dividedsections, the heights of all divided sections may be the same.

Among the plurality of sections, since section E is a section includingthe maximum horizontal diameter of the ice making cell, the volume ismaximum, and the volume decreases from section E to the upper sectionand the lower section.

As described above, assuming that the same amount of cool air issupplied and the output of the second heater 430 is constant, the icegeneration rate in the E section is the slowest, and the ice generationrate in the A section and section I is the fastest.

In this case, since the ice generation rate is different for eachsection, the transparency of the ice varies for each section, and thereis a problem that the ice generation rate is too fast in a specificsection, including air bubbles.

In the present disclosure, the second heater 430 is controlled so thatthe rate at which ice is generated for each section is the same orsimilar while allowing the bubbles in the water to move downward duringthe ice generation process.

Specifically, since the volume of the E section is the largest, theoutput W5 of the second heater 430 in the E section may be set as low asthe maximum. Since the volume of section D is smaller than the volume ofsection E, the rate of ice generation increases as the volume decreases,it is necessary to delay the rate of ice generation. Accordingly, theoutput W6 of the second heater 430 in section D may be set higher thanthe output W5 of the second heater 430 in section E.

For the same reason, since the volume of section C is smaller than thevolume of section D, the output W3 of the second heater 430 of section Cmay be set higher than the output W4 of the second heater 430 of sectionD. In addition, since the volume of section B is smaller than the volumeof section C, the output W2 of the second heater 430 in section B may beset higher than the output W3 of the second heater 430 in section C. Inaddition, since the volume of section A is smaller than the volume ofsection B, the output W1 of the second heater 430 in section A may beset higher than the output W2 of the second heater 430 in section B.

For the same reason, since the volume of section F is smaller than thevolume of section E, the output W6 of the second heater 430 of section Fis set higher than the output W5 of the second heater 430 of section E.Since the volume of the section G is smaller than the volume of thesection F, the output W7 of the second heater 430 of the section G maybe set higher than the output W6 of the second heater 430 of the sectionF. Since the volume of section H is smaller than the volume of sectionG, the output W8 of the second heater 430 in section H may be set higherthan the output W7 of the second heater 430 in section G. Since thevolume of section I is smaller than the volume of section H, the outputW9 of the second heater 430 of section I may be set higher than theoutput W8 of the second heater 430 of section H.

Accordingly, looking at the output change pattern of the second heater430, after the second heater 430 is turned on for the first time, theoutput of the second heater 430 may be gradually reduced from the firstsection to the intermediate section.

In the intermediate section of the ice making cell 320 a (the section inwhich the horizontal diameter is the maximum), the output of the secondheater 430 may be minimized. From the next section of the intermediatesection of the ice making cell 320 a, the output of the second heater430 may be increased step by step again.

As illustrated in FIG. 41 , as the height of the generated iceincreases, the temperature sensed by the temperature sensor 700decreases. The section reference temperature for each section may bedetermined in advance and may be stored in a memory (not illustrated).

Accordingly, when the temperature sensed by the temperature sensor 700in the current section reaches a section reference temperature of thenext section, the controller 800 may be changed to the output of thesecond heater 430 corresponding to the current section to the output ofthe second heater corresponding to the next section.

In FIG. 40(a), it is assumed that the pressing part does not exist inthe second tray 380 for easy understanding.

In the present embodiment, since the pressing part is provided in thesecond tray 380, actually, section I may not exist according to thenumber of sections in the ice making cell 320 a. Alternatively, sectionI may correspond to a section in which the pressing part is located.

In any case, the section including the pressing part may correspond tothe final section among the plurality of sections, and the output of thesecond heater 430 may be determined based on the volume of the section.

By controlling the output of the second heater 430, the transparency ofthe ice becomes uniform for each section, and bubbles are collected inthe lowermost section, so that bubbles are collected in a local part ofthe ice as a whole and the rest of the ice may be transparent as awhole.

FIG. 43 is a view for explaining a method for controlling a secondheater in a case in which defrosting of an evaporator starts in an icemaking process.

Referring to FIGS. 40 and 43 , while ice is started (S4) and ice isgenerated by turning on the second heater 430 during the ice makingprocess, the defrosting of the evaporator for supplying cold air to thefreezing compartment 32 can be started (S21).

As an example, defrost may be performed by turning on the defrost heater710, but it is noted that there is no limitation in the method ofperforming the defrost in the present disclosure.

When defrosting is performed by the defrost heater 710, the cold air maynot be supplied to the freezing compartment 32, the amount of cold airsupplied may be small, or the temperature of the supplied cold air maybe high.

Accordingly, during the defrosting process, the temperature of the coldair around the ice maker 200 increases, and accordingly, the temperaturesensed by the temperature sensor 700 is high.

As described above, when defrosting is performed while the second heater430 is operated, substantially the heat supplied to the ice making cell320 a becomes excessive. In this case, there is a problem in that ice isnot generated at a desired time period due to a slow rate of icegeneration, and there is a problem that the transparency of each sectionof the generated ice is changed.

Accordingly, when defrosting starts during the ice making process, thecontroller 800 may determine whether it is necessary to reduce theoutput of the second heater 430 (S22).

The controller 800 may determine whether the current section is asection before the intermediate section, and if the current section is asection before the intermediate section, it may determine that theoutput of the second heater 430 needs to be reduced.

For example, in FIG. 40 , when defrosting starts while ice is beinggenerated in section B, the controller 800 can reduce the output of thesecond heater 430 as an output (W3) corresponding to section C, which isthe next section.

In this way, by reducing the output of the second heater 430, excessiveheat may be prevented from being supplied to the ice making cell 320 a,and unnecessary power consumption of the second heater may be reduced.In this way, after reducing the output of the second heater 430, thecontroller 800 may variably control the output of the second heater 430for each section.

For example, in a state in which the output of the second heater 430 isreduced, the controller 800 determine whether the temperature sensed bythe temperature sensor 700 reaches the section reference temperaturecorresponding to the next section to the section in which the output isreduced. In addition, in a case in which the sensed temperature reachesthe section reference temperature corresponding to the next section, theoutput variable control of the second heater 430 is normally performed.

Specifically, when the defrosting starts while the second heater 430 isoperating at an output of W2 in section B, the output of the secondheater 430 is reduced and thus operates at an output of W3.

When the temperature sensed by the temperature sensor 700 reaches asection reference temperature corresponding to section C, which is thenext section of section B, the controller 800 controls the second heater430 to correspond to the output W3 of section C to work with the outputof W3. Sequentially, the output of the second heater 430 may be adjustedas an output corresponding to section D to section H.

In summary, the controller 800 reduces the output of the second heater430 only in the current section, and when the next section starts basedon the temperature change, the output variable control of the secondheater 430 can be normally performed in the next section (S7).

As described above, in a case in which the defrost start time is asection before the intermediate section, the delay time of icegeneration can be minimized by reducing the output of the second heater430.

Meanwhile, in a state in which the current section is an intermediatesection, the controller 800 may determine that the output of the secondheater is reduced or maintained. As an example, the controller 800 mayturn off the second heater 430 when the current section is anintermediate section (section E) and the temperature sensed by thetemperature sensor 700 is equal to or higher than the turn-off referencetemperature. In this case, the turn-off reference temperature may be setas the temperature of above zero.

Thereafter, when the temperature sensed by the temperature sensor 700reaches a section reference temperature corresponding to the nextsection (section F), the second heater 430 is operated as an output W6corresponding to the next section (section F), and the output variablecontrol of the second heater 430 is normally performed (S7).

In addition, when the current section is an intermediate section(section E) and the temperature sensed by the temperature sensor 700 isless than the turn-off reference temperature, the controller 800 maymaintain the output of the second heater 430 (S24).

Alternatively, the controller 800 may maintain the output of the secondheater 430 in a state in which the current section is an intermediatesection (section E).

In this way, while the output of the second heater 430 is maintained,when the temperature sensed by the temperature sensor 700 reaches thereference temperature for a section corresponding to the next section(section F), the second heater 430 is operated with the outputcorresponding to the next section (section F) to normally performvariable control of the output of the second heater 430 (S7).

On the other hand, in a case in which the current section is a sectionafter the intermediate section, since there is not much time remaininguntil the ice is completed, the controller 800 maintains the output ofthe second heater 430 as the current output, and until ice generation iscompleted, the output variable control of the second heater 430 may benormally performed.

Alternatively, in a case in which the current section is a section afterthe intermediate section, the controller 800 may maintain the output ofthe second heater 430 as the current output in the current section, andthen reduce the output of the second heater 430 when the temperaturedetected by the temperature sensor 700 reaches the reduction referencetemperature.

For example, the controller 800 may reduce the output of the secondheater 430 to the output of the previous section. Referring to FIG. 38 ,in a case in which the current section is the G section, when thetemperature sensed by the temperature sensor 700 reaches the reducedreference temperature, the output of the second heater 430 can bereduced to output W6 corresponding to section F which is the previoussection.

Thereafter, when the temperature sensed by the temperature sensor 700reaches a section reference temperature corresponding to the nextsection (section H), the second heater 430 is operated as an outputcorresponding to the next section (section H), and thus the outputvariable control of the second heater 430 can be normally performed. Inthis case, the reduced reference temperature may be set equal to orlower than the turn-off reference temperature.

According to the present embodiment, there is an advantage in thattransparent ice can be generated by adjusting the output of the secondheater in response to a temperature increase of the cold air around theice maker during the defrosting process.

FIG. 44 is a view for explaining a method for controlling a secondheater in a case in which a target temperature of a freezing compartmentis changed during an ice making process.

FIG. 45 is a graph illustrating a change in output of a second heateraccording to an increase or decrease in a target temperature of afreezing compartment.

Referring to FIGS. 44 and 45 , the amount of cool air (or the coolingpower or cool air temperature of the compressor) is determined inaccordance with the target temperature of the freezing compartment 32,and the determined amount of cool air is supplied to the freezingcompartment. The reference output of the second heater 430 for eachsection is determined in consideration of a predetermined amount of coolair.

However, when the target temperature of the freezing compartment 32 isvaried, the amount of cool air supplied to the freezing compartment 32is varied, and accordingly, the temperature of the cold air around theice maker 200 may vary.

If the target temperature of the freezing compartment 32 decreases, theamount of cool air supplied to the freezing compartment 32 increases, sothat the temperature of the cold air around the ice maker 200 decreases,thereby increasing the rate of ice generation. On the other hand, whenthe target temperature of the freezing compartment 32 increases, theamount of cool air supplied to the freezing compartment 32 decreases, sothat the temperature of the cold air around the ice maker 200 increases,thereby slowing the rate of ice generation. Therefore, the ice makingtime becomes longer.

Accordingly, in the present embodiment, the controller 800 may controlthe output of the second heater 430 so that transparent ice can begenerated at a constant ice making rate regardless of the variation ofthe target temperature.

For example, ice making starts (S4), and a target temperature change ofthe freezing compartment 32 is sensed through the input part 720 duringthe ice making process (S31). Then, the controller 800 determineswhether the target temperature increases (S32).

As a result of the determination in step S32, if the target temperatureis increased, the controller 800 reduces the reference output of each ofthe current section and the remaining section, and operates the secondheater 430 with the reduced reference output. Then, until the ice makingis completed, the output variable control of the second heater 430 foreach section may be normally performed (S35).

On the other hand, if the target temperature decreases, the controller800 increases the reference output of each of the current section andthe remaining section (S34), and operates the second heater 430 with theincreased reference output. Then, until the ice making is completed, theoutput variable control of the second heater 430 for each section may benormally performed (S35). In this embodiment, the reference output toincrease or decrease may be predetermined.

According to the present embodiment, by increasing or decreasing thereference output for each section of the second heater in considerationof a case in which the amount of cold air is varied according to thetarget temperature change, there is an advantage in that transparent icecan be generated at a constant ice making speed.

FIG. 46 is a view for explaining a method for controlling a secondheater in a case in which a door opening is detected during an icemaking process.

Referring to FIG. 46 , while ice making starts (S4) and ice is generatedby turning on the second heater 430 during the ice making process, theopening of the freezing compartment door 30 that opens and closes thefreezing compartment 32 may be detected. Of course, in a case in whichthe ice maker 200 is provided in the refrigerating compartment 18, theopening of the refrigerating compartment doors 10 and 20 may bedetected.

After the opening of the door is detected and the closing of the door isdetected, the controller 800 determines whether the temperature detectedby the temperature sensor 700 is higher than the reference temperatureof the current section (S42).

For example, when the door is opened, external air is supplied to thefreezing compartment 32, so that the temperature inside the freezingcompartment 32 rises. When the temperature inside the freezingcompartment 32 rises, the temperature around the ice maker 200 rises, sothat the temperature sensed by the temperature sensor 700 increases. Thelonger the opening time of the door, the greater the width of thetemperature increase.

As a result of determination in step S42, in a case in which thetemperature sensed by the temperature sensor 700 is higher than thereference temperature of the current section, the controller 800 reducesthe current output of the second heater 430. For example, the controller800 may turn off the second heater 430 (S44).

On the other hand, in a case in which the temperature sensed by thetemperature sensor 700 is not higher than the reference temperature ofthe current section, the controller 800 maintains the current output ofthe second heater 430. That is, in a case in which the door opening timeis short, since there is little temperature change, the output of thesecond heater 430 is maintained.

In a case in which the second heater 430 is turned off, the controller800 may determine whether the temperature sensed by the temperaturesensor 700 has reached the reference temperature of the next section(S45).

In a case in which the door is closed, the temperature detected by theturn-off temperature sensor 700 of the second heater 430 decreases, andwhen the sensed temperature reaches the reference temperature of thenext section, the controller 800 operates the second heater 430 as thereference output of the next section (S46). In which, until the icemaking is completed, the output variable control of the second heater430 for each section may be normally performed (S7).

According to the present embodiment, by controlling the second heater inconsideration of the temperature change of the freezing compartment dueto the door opening and closing, there is an advantage that transparentice can be generated at a constant ice making rate.

The present disclosure is not limited to the above-describedembodiments, and as can be seen from the appended claims, modificationsmay be made by those of ordinary skill in the field to which the presentdisclosure belongs, and such modifications are within the scope of thepresent disclosure.

Technical Problem

Embodiments provide an ice maker capable of providing transparent andspherical ice, and a refrigerator including the same.

Technical Solution

According to an aspect, an ice maker includes a first tray configured todefine a portion of an ice making cell, a second tray configured todefine another portion of the ice making cell, and a heater configuredto be disposed adjacent to any one of the first and second trays, inwhich the heater is turned on while cold air is supplied to the icemaking cell, and an output of the turned on heater is varied.

The second tray may be located below the first tray, and the heater maybe an ice maker positioned adjacent to the second tray rather than thefirst tray.

The heater may be in contact with the second tray.

A temperature of the heater may be maintained in a first temperaturerange by varying the output of the heater, may be maintained the secondtemperature range, and then may be maintained in the third temperaturerange. The average value of the first temperature range may be smallerthan the average value of the second temperature range. The averagevalue of the third temperature range may be smaller than the averagevalue of the second temperature range. The average value of the thirdtemperature range may be smaller than the average value of the firsttemperature range. During the ice making process, the output of theheater may increase. After the output of the heater increases, theoutput of the heater may decrease.

The output of the heater may be varied from a first output to a secondoutput and may be varied from a second output to a third output. Thesecond output may be greater than the first output, and the third outputmay be smaller than the second output. The third output may be smallerthan the first output.

A time driven by the first output may be shorter than a time driven bythe second output or driven by the third output.

According to another aspect, a refrigerator includes a storage chamberconfigured to store food; a cold air supply part configured to supplycold air to the storage chamber; a first tray configured to define afirst cell that is a space in which water is changed into ice by thecold air, a second tray configured to have a second cell to define anice making cell together with the first cell, and a heater configured tobe disposed adjacent to any one of the first and second trays, in which,for ice making, an output of the heater may increase to a second outputwhile the heater is operated with a first output.

Before completion of ice making, the output of the heater may be reducedto a third output that is smaller than the first output.

Advantageous Effects

According to an embodiment of the present disclosure, since the heatercontacts a tray made of a soft material as necessary, transparent ice ofvarious shapes, such as a spherical shape or a square shape, can beimplemented.

According to an embodiment of the present disclosure, in order to maketransparent ice, an area with a high ice making speed increases theheating amount of a heater to slow the ice making speed, and an areawith a relatively slow ice making speed decreases the heating amount ofthe heater to increase the ice making speed. In conclusion, by keepingthe ice making speed constant as a whole, transparent ice can beprovided to the user.

In addition, by controlling the heater in multiple stages, it ispossible to reduce the heating amount of the heater and increase theamount of ice making.

According to an embodiment of the present disclosure, heat is suppliedusing a heater adjacent to the first tray to separate ice from the firsttray, and additional heating is performed after rotating the second trayby a predetermined angle, thereby securing reliability of iceseparation. In addition, ice already separated from the first tray canbe prevented from excessively melting due to additional heating.

In addition, after separating the ice from the first tray, by waiting ina state in which the second tray is rotated by a predetermined angle,the phenomenon can be prevented that the residual water generated whenheating the first tray falls into the ice bin, and a mat of the icecubes is generated.

According to an embodiment of the present disclosure, ice may bedetected by rotating the full ice detection lever in a swing type. Inaddition, when ice is guided to the ice bin located at the bottom of thetray, it is possible to induce the ice to accumulate in one direction inthe ice bin, so that it is possible to detect whether ice is full evenin the ice bin with a low height.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. An ice maker comprising: a first tray configuredto define a first portion of a cell; a second tray configured to definea second portion of the cell; a heater configured to be disposedadjacent to one of the first tray and the second tray; and a controllerconfigured to control the heater, wherein the heater is configured to beturned on in at least partial section while cold air is provided to thecell, and wherein in a state in which the heater is turned on, thecontroller is configured to control the heater to vary an output of theheater according to a plurality of steps while the cold air is providedto the cell, wherein the plurality of steps comprises: a first stepwhere the controller is configured to operate the heater at a firstoutput greater than zero for a first time period; a second step wherethe controller is configured to operate the heater at a second outputgreater than the first output for a second time period, the second stepbeing performed subsequent to the first step; and a third step where thecontroller is configured to operate the heater at a third output lessthan the second output for a third time period, the third step beingperformed subsequent to the second step.
 2. The ice maker of claim 1,wherein the first step includes a plurality of sub-steps, or the secondstep includes a plurality of sub-steps, or the third step includes aplurality of sub-steps.
 3. The ice maker of claim 1, wherein the firsttime period is different from the second time period and the first timeperiod is different from the third time period.
 4. The ice maker ofclaim 3, wherein the first time period is shorter than the second timeperiod and the first time period is shorter than the third time period.5. The ice maker of claim 1, wherein the second time period is differentfrom the first time period and the second time period is different fromthe third time period.
 6. The ice maker of claim 5, wherein the secondtime period is longer than the first time period and the second timeperiod is shorter than the third time period.
 7. The ice maker of claim1, wherein the third time period is different from the first time periodand the third time period is different from the second time period. 8.The ice maker of claim 7, wherein the third time period is longer thanthe first time period and the third time period is longer than thesecond time period.
 9. The ice maker of claim 1, wherein the third timeperiod is longer than the first time period, or the third time period islonger than the second time period.
 10. The ice maker of claim 1,wherein the plurality of steps comprises a fourth step where thecontroller is configured to operate the heater at a fourth output equalto zero for a fourth time period.
 11. The ice maker of claim 10, whereinthe fourth time period is shorter than the third time period.
 12. Theice maker of claim 1, wherein at least one of the first output isgreater than a difference between the first output and the secondoutput, and greater than a difference between the second output and thethird output.
 13. The ice maker of claim 1, wherein at least one of thesecond output is greater than a difference between the first output andthe second output, and greater than a difference between the secondoutput and the third output.
 14. The ice maker of claim 1, wherein atleast one of the third output is greater than a difference between thefirst output and the second output, and greater than a differencebetween the second output and the third output.
 15. The ice maker ofclaim 1, wherein the third output is greater than a difference betweenthe second output and the third output.
 16. The ice maker of claim 1,wherein a difference between the first output and the second output isdifferent from a difference between the second output and the thirdoutput.
 17. The ice maker of claim 16, wherein a difference between thefirst output and the second output is less than a difference between thesecond output and the third output.